anki cards p/c
what is bond order
# of bonds between atoms (single, double, or triple)
How do we estimate whether a reaction has a decrease/increase in entropy
# of moles and phase cchanges. Less moles and more dense phases mean lower entropy
What are the possible values of Magnetic quantum number?
#NAME?
fluids and respiratory system
#NAME?
Describe the shape of a d orbital?
D-orbitals are mostly shaped like 4 leaf clovers, except for the donut dumbell version of the d orbital.
fluids and the circulatory system
#NAME?
What are the possible values of ms?
+1/2 if the electron is spinning up and -1/2 if the electron is spinning down.
What is pH?
-log[H+]
What are the common names associated with carboxylic acids?
1. Formic acid (Methanoic Acid) 2. Acetic Acid (Ethanoic Acid) 3. Propionic Acid (Propanoic Acid)
What are the 4 types of potential energies?
1. Gravitational 2. Elastic 3. Chemical 4. Electrical
ABC
123
Angstrom to meter
1A=1E-10m
In calculations involving standard entropy, enthalpy, or free energy (you see the degree symbol), temp is always ____
298K
What is the NMR shift associated with aromatic protons?
6 to 8.5 ppm
What is the definition of a Bronsted-Lowry base?
A Bronsted-Lowry base is a molecule that accepts H+ ions from another molecule (the Bronsted-Lowry acid).
When will a convex meniscus form?
A convex meniscus will form when the cohesive forces of the liquid are stronger than the adhesive forces (the liquid prefers sticking to itself over sticking to the walls of the container.)
What is a diol and how is it named?
A diol is a molecule with two alcohols. These molecules keep the -ane parent name and adds the suffix -diol
What is a Disproportionation Reaction?
A disproportionation reaction is a reaction in which one species is reduced and oxidized simultaneously. Example below. Usually accomplished by enzymes with metal ions such as Cu and Zn that act as reducing agents
What is the archetypal form of a double-displacement reaction?
A double-displacement reaction is when elements from two different compounds swap places with each other to form new compounds.
What is viscosity?
A fluid's resistace to flow. Thick fluids have high viscosity, thin fluids have low viscosity.
What is a pi bond?
A pi bond is a bond that occurs between two lined up p-orbitals. In this bond their electron clouds overlap and a bonding molecular orbital is formed.
What is a scalar?
A quantity with a magnitude only
What is a resistor?
A resistor is an electrical element that resists the flow of electrons through itself.
What is the archetypal form of a single-displacement reaction?
A single-displacement reaction is when an atom or ion in a compound is replaced by an atom or ion of another element.
What is the shape of the s orbital?
A sphere
What is a free body diagram?
A visual accounting of all the forces on an object.
What is energy density
Ability to produce power as a function of weight. Lower means you need more material to produce a certain output
What is the mass of a neutron?
About the same as a proton, 1amu.
What is acetone?
Acetone is the common name for propanone.
How do you remove protecting groups?
Acid
What are common dielectrics?
Air, glass, plastic, and ceramic.
Are aldehydes or ketones more reactive and why
Aldehydes due to less steric hundrance
What is a harmonic series
All possible frequencies that a string can support
What is alpha decay?
Alpha decay is when an unstable nucleus emits an alpha particle AKA Helium Nucleus. Doesnt penetrate shielding (like lead sheets)
What are some common paramagnetic materials?
Aluminum, copper, and gold
What does it mean to be isobaric and how does that affect the first law of thermodynamics equation?
An Isobaric process is one in which there is no change in pressure. Keeping pressure constant does not affect U = Q-W
What is an electrode?
An electrode is the general name for the materials that make up the cathode and anode.
What is an enolate?
An enolate is a deprotonated enol. Enolates are better nucleophiles than enols.
What is an isolated system? Can internal energgy change?
An isolated system is a system that is incapable of exchanging energy or matter with its surroundings. It follows that the total change in internal energy in an isolated system will be equal to 0.
What is an orbital?
An orbital is a region of space outside of the nucleus where electrons can be found.
What is an oxime?
An oxime is a modified version of an Imine. In this molecule, the double bonded nitrogen has a hydroxyl group attached.
What does it mean to be an unsaturated solution?
An unsaturated solution is a solution that has not reached the maximum amount of dissolved solute as defined by the ksp. Solute added to an unsaturated solution will dissolve.
How big must the difference in electronegativity be to be considered a non-polar bond?
Any electronegativity difference less than 0.5 is considered a non-polar bond
As pressure on a liquid goes up, solubility of gases in that liquid [increases or decreases?]
As pressure on a liquid goes up, solubility of gases in that liquid increases
As the electric field between the plates in a capacitor increases, the capacitance [...]
As the electric field between the plates in a capacitor increases, the capacitance decreases
What is atomic weight?
Atomic weight is the weighted average of all the different stable isotopes one might find of an atom. For example, Chlorine naturally occurs in the 35 and 37 mass number. Therefore, the atomic weight of chlorine is equal to the weighted average of the mass number of its naturally occurring isotopes.
Which is the second quantum number?
Azimuthal (angular momentum) number, l.
Equation for blood pressure
BP=Cardiac output*total peripheral resistance
What is the formula for volumetric expansion?
Beta is volumetric expansion coefficient
Where are metalloids on the periodic table?
Between the metals and nonmetals.
Bonding orbitals are [higher or lower energy?] than antibonding orbitals
Bonding orbitals are lower than antibonding orbitals This also means they are more stable! This represents chemical bonds we typically see. atoms together are lower energy than atoms apart
Where in relation to the element symbol are the atomic number and mass number located?
Bottom left and top left, respectively.
What is Charles's Law?
Charles's law states that the volume and temperature of a gas are proportional.
What are conservative forces?
Conservative forces are forces that do not dissipate energy e.g Gravity and Electrostatics PATH INDEPENDENT
What are diffraction gratings
Consist of multiple slits arranged in patterns. Create colorful patterns similar to a prism as the different wavelengths interfere in characteristic patterns
When multiplying vectors, what type of product should be used to create a new vector?
Cross Product
What are the 6 major kinds of reactions seen on test day?
1. Combination 2. Decomposition 3. Combustion 4. Single Displacement 5. Double Displacement 6. Neutralization
What are the three carboxylic acid derivatives?
1. Esters 2. Amides 3. Anhydrides
What are the solubility based extraction procedures?
1. Extraction 2. Filtration 3. Recrystallization
What are five common names associated with aldehydes?
1. Formaldehyde - Methanal 2. Acetaldehyde - Ethanal 3. Propionaldehyde - Propanal 4. butyraldehyde- butanal 5. valeraldehyde- pentanal
What is the naming convention for 1, 2, 3, and 4 carbon molecules?
1. Methane 2. Ethane 3. Propane 4. Butane Note, the (ane) is just what these would be called if they were alkanes. The root is what is important here.
What are the 5 ways to express concentration?
1. Percent composition by mass 2. Molarity 3. Molality 4. Normality 5. Mole fraction
List the 7 types of electromagnetic radiation represented in the electromagnetic spectrum from lowest energy to highest energy.
1. Radio Waves 2. Microwaves 3. Infrared Waves 4. Visible Waves 5. UV rays 6. X-Rays 7. Gamma Rays
What are the four fundamental forces?
1. Strong Nuclear Force 2. Weak Nuclear Force 3. Gravitational Force 4. Electromagnetic Force
What are the 4 colligative properties?
1. Vapor pressure 2. Boiling point 3. Freezing point 4. Osmotic Pressure
What is the NMR shift associated with carboxylic acid protons?
10.5 to 12 ppm
Max # of electrons in an orbital
2
What is the NMR shift associated with alkyne protons (sp hybridized carbons)?
2 to 3 ppm.
Sin(30)=
2-Jan
converting ppm or ppb to molarity
200ppb means 200grams per 109 grams water Use density of water and dimensional analysis to get to mol per liter
What is body temperature in celsius and farenheit?
37, 98.6
What is Planck's constant equal to with units
6.626*10-34 J*s
What is a conjugate base?
A conjugate base is the base formed when an acid gives a proton to some other base.
What is a crest?
A crest is the highest point a wave reaches.
What is a dehydration reaction?
A dehydration reaction is a reaction that gives off water. These are usually also condensation reactions.
What is a Lewis base?
A lewis base is an electron pair donor.
What is a longitudinal wave?
A longitudinal wave oscillates in the same direction as the movement of the wave. Particles of wave oscillate parallel to the direction of energy transfer
What is a node?
A node is a point on a standing wave at which there is no amplitude.
What is a period in regards to the periodic table?
A period is a horizontal row on the periodic table.
What is a photon?
A photon is a massless wave-like and particle-like packet of electromagnetic (light) energy.
What is a reversible reaction?
A reversible reaction is a reaction that will establish an equilibrium and exist in some combination of products and reactants.
What is a spectator ion?
A spectator ion is an ion that stays in the aqueous form and keeps its oxidation number after the reaction is complete. In other words, spectator ions don't change during the reaction, they are just spectating.
When will an acid-base reaction proceed spontaneously, based on the strength of the reactants and the products?
Acid base reactions only proceed spontaneously if the products are weaker in terms of acidity and basicity than the products.
What is pOH?
-log[OH]
What are the possible values for l?
0 to n-1
What are the three ways to calculate work done on or by a system?
1. 2. 3.
What are some functional groups that commonly act as bases?
1. Amines 2. Amides
What are the three definitions of acids and bases?
1. Arrhenius 2. Bronsted-Lowry 3. Lewis
How are aldehydes named as substituents and parent chains?
1. Carbonyl substituents, whether they are aldehydes or ketones, are given the name (oxo-) 2. Aldehyde parent chains replace the -e of the parent name with -al
What are the axes of an NMR spectra?
1. Chemical shift in units of parts per million, increases as it goes left, not right. 2. Absorbance, which corresponds to the number of protons. Chemical shift is an arbitrary unit that is used to standardize NMR spectra.
What are the two types of electrochemical cell?
1. Galvanic (Voltaic) cell 2. Electrolytic cell
What are common ammonia derivatives that react with aldehydes and ketones?
1. Hydroxylamine, H2N-OH, forms Oximes 2. Hydrazine, H2N-NH2, forms Hydrazones 3. Semicarbazide, H2N-NH-C(O)NH2, forms Semicarbazones.
What are the various types of column chromatographies?
1. Ion Exchange Chromatography 2. Size Exclusion Chromatography 3. Affinity Chromatography (Note: All of these are covered in depth in the biochemistry flashcards.)
What are the 4 types of thermodynamic processes?
1. Isothermal 2. Adiabatic 3. Isobaric 4. Isovolumetric
What are the important points and lines of the phase diagram?
1. The solid<>gas equilibrium line 2. The solid<>liquid equilibrium line 3. The gas<>liquid equilibrium line 4. The triple point 5. The critical point
What is the difference between ammonia and ammonium?
Ammonia is the deprotonated basic form, NH3. Ammonium is the protonated acidic form, NH4
If the equilibrium constant for a reaction written in one direction is Keq, what is the equilibrium constant of the reverse reaction?
1/Keq
What is amplitude in the context of waves?
Amplitude is the maximum possible displacement for a wave. NOT total distance from crest to trough (that would be twice the amplitude)
What are the ideal bond angles for a carbon with 3 bonds (sp2)?
120 degrees
Tesla to gauss
1T=104 gauss
How much volume does one mole of an ideal gas take up at STP?
22.4 Liters
Maximum number of electrons within a shell
2n2 n=principle quantum #
What is the speed of light equal to in a vacuum?
3*108m/s
What is the speed of light in air equal to?
3.00*108 m/s
What is the speed of sound in air at 20 celsius
343 m/s
What wavelength is associated with the color violet?
380ish nm
1cal=
4.184 Joules
What is the NMR shift associated with alkene protons (sp2 hybridized carbons)?
4.6 to 6 ppm
Maximum number of electrons within a subshell
4l+2
Value of G
6.67E-11
What wavelength is associated with the color Red?
750ish nm
Common values for R and associated units in equation
8.314 J/mol*K (use pascal and m3 in ideal gas law), .0821 (L*atm)/(mol*K)
What is the NMR shift associated with aldehyde protons?
9 to 10 ppm
What is an aldol?
An aldol is a molecule with an aldehyde and an alcohol. Note, that aldol reactions are still called aldol reactions, even when its actually a ketone and an alcohol.
What is a barometer?
A barometer is a device that measures the pressure of something.
What is the bronsted-lowry definition of an acid?
A bronsted-lowry acid is a molecule that donates a hydrogen to another molecule (the bronsted-lowry base)
What is a conformational isomer?
A conformational isomer is a type of stereoisomer that is a result of the free rotation around single bonds. At any point, a single bond might rotate into a different conformation and become a stereoisomer with a different rotational conformation. Same molecule, no bond breaking required. Just rotating
What is a cross product?
A cross product is the product of the magnitude of two vectors and the sin of the angle between them.
What is a meniscus?
A curving of the surface of a liquid in a container that is due to the cohesive and adhesive forces in the liquid.
What is the archetypal form of the decomposition reaction?
A decomposition reaction is when one reactant breaks down into two or more products.
What is a Fischer projection?
A fischer projection is a way of representing 3D molecules in 2D space. The fischer projection is a cross where the center is the carbon of interest, the vertical arms are moving away from you, and the horizontal arms of the fischer projection are coming out at you. It is not optional that the arms of the fischer projection are coming out at you. Notice in the molecule below how the carbon 3rd carbon had to get rotated so that the fischer projection would be correct.
What is a homogenous catalyst?
A homogenous catalyst is a catalyst that is in the same phase (gas, liquid, solid) as the reactants.
What is a jones oxidation?
A jones oxidation is just a very strong oxidation. It is conducted by using CrO3 with dilute Sulfuric Acid H2SO4 and Acetone in aqeuous conditions. Although this oxidation is very strong and has its own name, it acts just like any other strong oxidizer would.
What is a lactone?
A lactone is a cyclic ester. Like lactams, they are often named according to greek lettering.
What is a Lewis acid?
A lewis acid is an electron pair acceptor.
What is a mesylate?
A mesylate is a compound containing the functional group -SO3CH3. Mesylates are good leaving groups. Mesylates are prepared by using methylsulfonyl chloride on an alcohol in the presence of a base. derived from methanesulfonic acid
What is a normal?
A normal is a line that is perpendicular to a surface.
What is a nucleophile?
A nucleophile is an atom that is attracted to the positive charge of the protons in the nucleus of other atoms. Generally nucleophiles have lone pairs or pi bond electrons that can attack electrophiles.
Diverging optics have [positive or negative?] focal lengths.
Diverging optics have negative focal lengths.
How do we calculate binding energy?
E=mc2 m= mass defect (difference between sum of protons and neutrons and the actual measured mass) c= 932 Mev/amu
What does it mean to have an eclipsed newman projection?
Eclipsed newman projections occur when the substituents are lined up with one another. These can be in either Eclipsed or Totally Eclipsed conformation. High energy, low stability
What is effusion?
Effusion is the flow of a gas particle under pressure from one area to another through a small opening.
What are common electron withdrawing groups?
Electron withdrawing groups are generally groups that have high electronegativity and pull electrons towards themselves.
What conformation does cyclopentane take to make ring strain as low as possible?
Envelope
equivalence point vs end point
Eq point is when moles of acid=moles of base end point is when indicator changes color (always a bit different than eq point)
Formation of mono, di, tri acylglycerols,
Esterification. OH on glycerol attacks carbonyl carbon of carboxyl group on fatty acid
What is Hooke's Law
F=-kx
What is a phenol?
A phenol is an aromatic ring with an alcohol. Their characteristic property is that their alcohol hydrogen is way more acidic than normal alcohol hydrogens. This is because the negative charge of the conjugate base can stabilize itself in the aromatic ring.
Describe the formation of cyanohydrins.
First, hydrogen cyanide dissociates into its constituent ions. Then the nitrogen electrons attack the carbonyl carbon. The double bond electrons are pushed up to the oxygen which then protonates, forming a cyanohydrin.
What is a potentiometric titration
Form of redox titration where a voltmeter is used as opposed to an indicator (analogous to acid-base titration with pH meter)
What is frequency?
Frequency is the number of full oscillations a wave completes in one second.
In what direction(temperature wise) does heat flow?
From objects with high temperatures to objects with lower temperatures
How do we calculate g?
GMearth/r2
Generally speaking, the valence electrons determine the [...]
Generally speaking, the valence electrons determine the way an atom reacts and its chemical properties
What is Gravity Filtration?
Gravity filtration is when the liquid and solid just pass through the filter because gravity pulls them through it. This is the preferred method when you are more concerned with pure filtrate, as it is less likely that any residue will make it through the filter. Hot solvent is used to ensure product is dissolved
If the frorward reaction is spontaneous, what is Keq?
Greater than 1
Phosphoric acid
H3PO4
What are the two types of energy transfer?
Heat(thermal) and Work(mechanical)
How does binding energy relate to stability
Higher binding energy means lower energy nucleus means more stable Fe is most stable aka has highest binding enrgy In general mid size elements have highest binding energies and are most stable
Entropy definition in regards to energy
Higher entropy means higher energy distribution
Which component of a vector will cos(theta) give you? (horizontal/vertical and parallel/perpendicular)
Horizontal or Perpendicular
What is hydration?
Hydration is the same thing as solvation, it's just what you call it when water is the solvent.
In what direction will the reaction proceed if Q = Keq? What is ΔG?
If Q = Keq then the reaction is at equilibrium. The delta G is equal to 0 and the reaction will stay where it is.
In what direction will the reaction proceed if Q > Keq? What is ΔG?
If Q > Keq then the ratio of products to reactants is higher then it would be at equilibrium. Therefore, we'd expect the reaction to go in the reverse direction to reach the equilibrium ratio. ΔG is positive
What is a reaction mechanism?
In a reaction that is expected to take more than one step, the reaction mechanism is the proposed series of steps.
In an electrolytic solution, as concentration of ionic solutes goes up, conductance [...]
In an electrolytic solution, as concentration of ionic solutes goes up, conductance increases
What is an overtone?
In an object that produces multiple frequency waves when struck, the overtones are the higher frequency waves.
How does a polar protic/ aprotic solvent affect nucleophilicity
In polar protic it increases down the periodic table (I is better than F) In polar aprotic it increases up the periodic table (F is better than I)
In what direction will charges spontaneously move?
In the direction of lower electric potential energy.
How does capacitor plate distance affect energy stored (isolated vs connected)
Isolated: Linear relationship. Cutting distance in half decreases energy stored by one half (capacitance doubles but voltage has to decrease) doubling distance doubles energy Connected: cutting distance in half will double energy stored since voltage remains constant yet capacitance doubles. Doubling distance will cut energy stored in half Just use your equations and this makes sense
What is the energy barrier?
Just another term for Activation Energy, Ea
Units for Newton
Kg*m/s2
What can reduce an ester
LiAlH4
What is the molecular geometry associated with 2 bonding pairs and 4 lone pairs
Linear
Important thing to remember when performing any reaction involving an alpha hydrogen
MAKE SURE THERE ACTUALLY IS AN ALPHA HYDROGEN
What is molality?
Molality is the ratio of the moles of solute to the kilograms of the solvent.
What is molar mass?
Molar mass is how much mass you will have of something given a mole of it. It is usually expressed in g/mol
What is molecular formula?
Molecular formula is the exact number of atoms of each element in the compound, without being reduced to simplest whole number ratios.
Higher Ksp means more or less soluble
More soluble
Whate are the uses of TLC
Most frequently used on a small scale to identify unknown molecules Can be used as a purification method (preparative TLC) in which a large spot is placed on a large plate. As the plate develops the spot will split into bands of individual components which can be scraped off and harvested
Moving a charge along an equipotential line [...]
Moving a charge along an equipotential line requires no work
What is a vector
A quantity with a number and a direction
What is an organic phosphate?
An organic phosphate is a phosphate containg compound that also contains carbons. ATP, GTP, Nucleotides, etc are all organic phosphates.
What is an oxidation number?
An oxidation number is the number of redistributed electrons on an element in a compound or on its own.
What is electrolysis
An oxidation reduction reaction driven by an external voltage (aka electrolytic cells)
As temperature increases vapor pressure [increases or decreases?]}}
As temperature increases vapor pressure increases}}
As the polarity of the bonds increases, [What kind of intermolecular force increases?]
As the polarity of the bonds increases, Dipole-Dipole interactions increase
How to modify coulombs law when given charges that are +2/3/4 any other integer
Multiply the fundamental unit of charge by the charge
Units of a pascal
N/m2
How do you name compounds with 2 double bonds?
Name both carbon numbers and give it the name diene. Similar process for tri-enes
Whats the only way to determine whether a beam will stay still when forces are applied to either side
Net torque must be 0. Net force DOES NOT have to be 0.
Are catalysts used up?
No they are not permanently changed
Can acid anhydrides easily form aqueous solutions
No, they are reactive in water and thus will turn into carboxylic acids
Can a catalyst ever make a nonspontaneous reaction spontaneous?
No. Catalysts only affect the activation energy of the reaction, not the delta G.
How stable are hemiacetals and hemiketals
Not that stable, the alcohol will protonate and peace out in the presence of acid
What happens if a molecule hits another molecule with less energy than the activation energy of the reaction?
Nothing will happen. If the reaction is to occur, the activation energy must be surpassed.
What is one hertz equal to?
One cycle per second 1Hz = 1/s
Only charges moving with a [...] component to the magnetic field will feel a force of any sort.
Only charges moving with a perpendicular component to the magnetic field will feel a force of any sort.
Open boundaries always correspond to [...]
Open boundaries always correspond to antinodes
What is Osmotic Pressure?
Osmotic pressure is the "sucking" pressure generated by solutions that draw water into themselves because of the concentration gradient.
What kind of liquids exhibit osmotic pressure?
Osmotic pressure is the pressure associated with concentration gradients of solutes. Therefore, any fluid with dissolved solutes will exhibit osmotic pressure.
How do paramagnetic materials behave when exposed to magnets?
Paramagnetic materials become weakly magnetized by and attracted to the magnet.
What are the 5 units in which pressure is measured?
Pascals, mmHg, torr, atm, bar
What bonds in AA have free rotation and which don't
Peptide bond doesnt due to partial double bond character from resonance Bonds on either side of peptide bond do
Describe Poiseuille's Law?
Poiseuille's Law is a method by which one can calculate the rate of flow through a confined space (or pipe) of some sort. Only with laminar flow
Describe the appearance of polyvalent titration curves?
Polyvalent titration curves will represent the equivalence points of all of the reactions in the polyvalent species. That means, for a polyvalent acid, let's say a diprotic acid, there would be two equivalence points on the curve. The first would correspond to the completion of the first dissociation reaction, and the second would correspond to the completion of the second dissociation reaction.
How does one calculate the change in entropy of a reversible process?
Q is heat gained or lost in a reversible process, T temp in kelvin
What is radiation? How is it unique?
Radiation is the transfer of energy by electromagnetic waves. Radiation is unique in that it requires no contact whatsoever with a material to exert its effects. In fact, radiation can even transfer energy through a vacuum.
Diastereomers optical acitivty
Random. Can differ in magnitude and sign
Which type of image can be projected onto a screen?
Real images
Torr to mmHg
Same
Describe the -NH IR peak
Sharp peak around 3300cm-1 usually shorter than OH peaks
Shell vs subshell vs orbital for electrons
Shell is energy level: subshell is s, p , d ,f ex. so shell 2 has subshells s and p p has 3 orbitals with 2 electrons each
What kind of bonds make up a single bond?
Sigma bond
What is solubility?
Solubility is the maximum amount of a substance that can be dissolved in a particular solvent at a particular temperature.
What is a sparingly soluble salt
Solutes that dissolve minimally in solvent, molar solubility below .1M
What is speed?
Speed is a scalar quantity that tallies the length of distance travelled over time.
What is a static equilibrium?
Static equilibrium is when the reaction is at equilibrium because neither the forward nor the reverse reaction are occuring at all.
If you see tert butyl what should you think
Steric hindrance
How is a peptide bond hydrolysed
Strong acid or base
Strong acids and bases have [strong, weak, or negligible?] conjugates?
Strong acids and bases have negligible conjugates?
What is it called when a solid goes to a gas?
Sublimation
What types of streches and bends can molecules undergo?
Symmetric and Asymmetric bends and stretches
What is the purpose of TMS?
TMS is used to standardize NMR spectra. TMS will always be calibrated to be equal to 0 ppm. When counting peaks to determine the number of hydrogens in a molecule, skip the TMS peak because its just the standard.
What is the LUMO?
The LUMO is the Lowest Unoccupied Molecular Orbital. This is the lowest energy level that the electrons can be promoted to.
What is the law of reflection?
The angle that the incident ray makes relative to the normal will equal the angle that the reflected ray makes relative to the normal.
What is bond length?
The average distance between the two nuclei of atoms in a bond.
What is temperature proportional to and founded upon?
The average kinetic energy of the particles that make up a substance.
What is energy?
The capacity to do work
What is the common ion effect?
The common ion effect states that the solubility of a solution can be affected by adding other substances.
How do dielectrics affect isolated capacitors?
The dielectric will lower the electric field of the isolated capacitor, which will lead to a decrease in voltage and an increase in capacitance.
What does the principle quantum number represent?
The energy level in which the electron resides.
What is the equivalence point?
The equivalence point is the point at which the reaction between the titrand and the titrant is completed. (all of the species has been deprotonated)
What is Entropy?
The extent to which a system is spread out/unorganized. The more spread out/ the less organized the more entropy.
What is cohesion?
The force of attraction that the molecules that make up a fluid feel with other molecules of that same fluid.
Which is the third quantum number?
The magnetic quantum number, ml
What quantity will be equivalent before and after a dilution?
The moles of solute present.
The more substitued a double bond the more [stable or unstable?] it is.
The more substitued a double bond the more stable it is.
In optics, all angles are measured from what line?
The normal line
What is the atomic number of an element equal to?
The number of protons in the element's nucleus
What is the triple point?
The point on the phase diagram where the gas, liquid, and solid phases are in equilibrium.
What is a system in the context of thermodynamics?
The portion of the universe we are interested in observing or manipulating. The rest of the universe is the surroundings.
What is a rate law?
The rate law is just another term for the rate equation.
What does an Ohmeter measure?
The resistance of a circuit element. Does not require circuit to be on unlike voltmeter and ammeter. Often has its own battery of known voltage. Also has ammeter function to get current. Can calculate resistence from known voltage and current. Neglidgeable resistence
Which is the fourth quantum number?
The spin quantum number, ms
Describe the tail to tip method?
The tail to tip method is a way of calculating the sums (or substractions) of vectors. Simply put the vectors tail to tip (flip the vector for negative)
What is nucleon number conservation
The total number of neutrons plus protons remains the same, even if neutrons are converted to protons and viceversa
What is Kw
The water dissociation constant. It is the equilibrium constant associated with the auto ionization of water.
What are the general characteristics of metalloids?
There are no general characteristics of metalloids. Each metalloid is distinct from the other with a combination of both metal and nonmetal characteristics.
How do catalysts modify reaction diagrams?
They lower the activation energy by lowering the energy of the transition state.
What kinds of molecules make good reducing agents?
Things that get oxidized well (i.e. try to lose electrons). Usually contain metal ions or hydrides (think: metals usually lose electrons)
What is Torsional strain?
Torsional strain is resulting from the repulsion of the electrons forming the bonds of two adjacent carbon atoms. We talk about torsional strain mainly when we draw Newman projection in the case of Eclipsed and Staggered.
What is turbulent flow?
Turbulent flow is rough and disorderly flow that causes the formation of eddies, which are swirls of fluid. This type of flow dissipates energy.
What are vicinal diols?
Vicinal diols are diols with the hydroxyl groups on adjacent carbons.
What environment should esterification reactions NOT be carried out in
Water! It will hydrolyze the desired products
How do we signifiy groups that are bound to nitrogens in nitrogen containing compounds?
We use the prefix N- instead of a number to indicate that the group is bonded to a nitrogen.
When does light refract towards the normal?
When light passes from a low index of refraction to a higher index of refraction.
When rotating a fischer projection, if you hold one substituent constant and rotate around the other 3 the stereochemistry will be [retained or inverted?]
When rotating a fischer projection, if you hold one substituent constant and rotate around the other 3 the stereochemistry will be retained
What is nuclear fusion?
When small nuclei combine to form a larger nucleus.
When does laminar flow convert to turbulent flow?
When the fluid's critical speed has been exceeded.
When waves are in phase, they will always [...]
When waves are in phase, they will always constructively interfere
How do buffer solutions resist changes in pH?
When you add straight up OH- or H+ to a buffer solution, the buffer equilibrium will respond to the change and compensate for it, according to Le Chatelier's principle. This is different in a non buffer solution where the H+ or OH- you add just gets added to the solution straight up without any response.
How does one relate the equilibrium constant for a reaction and the standard gibbs free energy of the reaction?
Where R is the ideal gas constant 8.314, T is the temperature, and Keq is the equilibrium constant.
How does one calculate power in terms of work?
Where W is work, t is time, and E is total mechanical energy
How does one calculate the velocity of a wave?
Where f is frequency and lambda is wavelength.
What is the formula to calculate an object's kinetic energy?
Where m is mass and v is speed
What is the formula for static friction?
Where us is the coefficient of static friction and N is the magnititude of the normal force.
Alternate way to tell enodthermic vs exothermic
Which side light is on, or any energy input for that matter. If it is on left, you have endothermic
What are some common diamagnetic materials?
Wood, plastics, water, glass, and skin
Do all atoms release energy when gaining an electron?
Yes, but to different extents
If frequency of light is equal to threshold frequency of metal, will electrons be ejected?
Yes, they will have 0 kinetic energy though
What should the change in total mechanical energy of an object be equal to when only dealing with conservative forces?
Zero
Henry's law
[A]=Kh*PA or [A]2/P1=[A]2/P2 Concentration of gas dissolved is directly proportional to partial pressure of gas at surface
What are infrasonic and ultrasonic waves
below and above the threshold for human hearing, respectively.
In parallel, adding more resistors ______ equivalent resistence
decreases!
Evaporation is endothermic or exothermic
endothermic
How do you name an acid of the form HA, where A is a single anion?
hydro- anion name - ic acid.
What are the six simple machines
inclined plane, wedge, wheel and axle, lever, pulley, and screw
Shielding effect trend
increases down (more elctrons blocking valence from nucleus)
What is the formula to calculate efficiency?
load equals weight
Equation to determine energy of subshell
n+l (add first two quantum numbers)
What does a catalyst speed up
progression towards equilibrium
Are electrical potential energy and electric potential scalars or vectors?
scalars
How do you know how much "s character" a bond has
sp3 is 25% sp2 is 33% sp is 50% literally just basic math
What can change the rate constant
temperature
If a substance strongly absorbs one color and reflects all others, we see
the absorbed colors complimentary color
How does one calculate the power of a lens?
where f is the focal length in meters.
change in potential energy is equal to
work
sin75
~1
What kind of bonds make up a triple bond?
A sigma bond, and 2 pi bonds perpendicular to the axis of the sigma bond and each other.
What is a transverse wave?
A transverse wave oscillates perpendicular to the direction of movement of the wave. Particles in the wave oscillate perpindicular to the direction of energy transfer
What is adhesion?
Adhesion is the attractive force that a molecule feels towards molecules of some other substance.
At what point will heat affect the temperature of an object that is undergoing a phase change?
After the phase change is complete. Changing phases requires its own heat energy and this cost must be paid first. Therefore, heat added to a 0 degrees celsius icecube will only cause the icecube to melt into water, not change the temperature. Once the ice cube is completely water, any additional added heat will raise the temperature.
Describe a Lead-acid battery
Aka Lead storage battery (specific type of rechargable battery) When fully charged it consists of two half-cells, a Pb anode and a porous PbO2 cathode, connected by a conductive material (concentrated sulfuric acid) When fully discharged it consists of two PbSO4 electroplated lead electrodes with a dilute concentration of sulfuric acid For discharge (functions as voltaic cell) Reduction half reaction (occurs at positive lead oxide cathode): PbO2 (s) + SO42- (aq) + 4H+ + 2e- -> PbSO4 (s) + 2H2O Oxidation half reaction (occurs at negative lead anode): Pb (s) + HSO4- (aq) -> PbSO4 (s) + H+ (aq) + 2e- For charging (functions as an electrolytic cell) These equations and electrode charge designations are opposite Very low energy density
What is the definition of an arrhenius acid?
An arrhenius acid is something that dissociates to form an H+ ion.
What does it mean for an atom to be in an excited state?
An atom is excited when one of its electrons is in a higher energy shell than it would normally be.
What is an electrical dipole?
An electrical dipole is when 2 equal positive and negative charges are separated by a small distance.
What is an enol?
An enol is a molecule with a double bond and an alcohol.
What is an isomer?
An isomer is a molecule with a different structure but the same molecular formula as another.
What is Netwon's Second Law?
An object of mass m will accelerate when the vector sum of the forces results in some nonzero resultant force vector.
Describe electric fields
Any given charged particle will create an electric field that radiates outward or inward in all directions. Charged particles that enter the electric field of a different object are liable to experience electrostatic forces.
What phase combos can make solutions
Any phase in liquid, any phase in solid, gas in gas, liquid in gas, solid in gas???
Describe the oxidation of aldehydes and what reagents
Anything stronger than PCC chromium stuff, Ag2O, H2O2, KMnO4
What is the loop rule?
Around a closed circuit loop, the sum of voltage sources will always be equal to the sum of voltage drops. Sum of all voltage will be 0 (source is pos and drops are neg)
What is avogadros principle
As # of moles of gas increases, volume increases in direct proportion 1 mol=22.4L 2 mol= 44.8L
If it doesn't say whether the potential given is oxidation or reduction, how can you tell?
Assume that it is whatever the equation is showing. If the equation is showing oxidation we have an oxidation potential
What is happening when an electron is promoted to a higher energy level?
Atoms gain energy all the time from increases in temperature, collisions with other atoms, and from being struck by photons (most common method). If an atom gains the exact amount of energy required to promote an electron from one energy level to another, it will do so.
Atoms will gain or lose electrons in such a way so as to achieve a [...]
Atoms will gain or lose electrons in such a way so as to achieve a noble gas configuration
What physical property does distillation take advantage of to separate compounds?
Boiling point!
What is bond dissociation energy?
Bond dissociation energy is the average energy that is required to break a particular type of bond between atoms in the gas phase. Some sample bond dissociation energies are shown below.
What is Boyle's Law?
Boyle's Law states the pressure and volume of a gas are inversely proportional.
What does it mean to be amphiprotic
Can gain or lose a proton (behave as bronstead lowry acid and base)
Naming of oxyanions
ClO- = hypochlorite ClO-2 =chlorite ClO-3 =chlorate ClO-4 perchlorate
To interpret anything about reaction rates we NEED ____
DATA ON RATES
What is the unit of sound?
Decible dB
What does damping decrease and what isnt affected
Decreases amplitude which decreases intensity which decreases sound level (loudness). Does not decrease frequency so pitch remains the same in dampened waves
What is it called when a gas goes to a solid?
Deposition
Most common use for a bomb calorimeter
Determine enthalpy of combution for hydrocarbons
What types of alcohols make the best protecting groups
Diols that are the least sterically hindered and can form a cyclic diol when protecting. Diols shouldnt contain trans double bond or it wont be able to be cyclic.
DC vs AC current
Direct current (charge flows in one direction only) Alternating current (charge changes direction periodically)
Alkyl groups are electon (donating or withdawing)
Donating
Energy of the electron equation
E= -(RH/n2) RH is Rydberg unit of energy (2.18E-18 J/electron) Energy of electron gets higher (more positive) as it travels farther from proton)
What are enantiomers?
Enantiomers are nonsuperimposable mirror images of one another. Your left and right hand would be examples of enantiomers
Force between capacitor plates
F=QE/2
Describe Filtration?
Filtration isolates a solid from a liquid. In this method, one pours a liquid-solid mixture through a filter of some sort (usually a paper filter). The liquid will pass through and fill a flask. This is known as filtrate. The solid on the other hand will be left in the filter. This is known as residue.
How do we know how many valence electrons an atom is carrying?
Find the atom's element on the periodic table and make note of what column it is in. That will tell you the number of valence electrons on that element, and therefore an atom of that element.
For a molecule with n chiral carbons, it will have a total of [...] stereoisomers?
For a molecule with n chiral carbons, it will have a total of 2n stereoisomers?
How does the common ion effect work?
For a soluble substance, if either of the constituent ions are present, they will appear in the products of the solvation equilibrium, and push the equilibrium left towards the precipitate, as predicted by le chatelier's principle. Solubility is reduced if dissolving in a solution that already has some of the ions vs pure solvent
Transition metal charges can be identified with roman numerals, but they can also be identified with suffices. What are these suffices?
For transition metals with two stable ions, the suffix -ous is used to refer to the lesser charge ion and the suffix -ic is used to refer to the higher charge ion.
What is the frequency factor, A?
Frequency factor is how many molecules collide per second.
As you move from left to right on the periodic table, in what way do elements change?
From left to right elements have an increasing number of protons, electrons, and neutrons. More specifically, going from left to right increases the effective nuclear charge in an atom.
What is Gibbs free energy?
Gibbs Free energy is the amount of "available" energy associated with a reaction. When Gibbs energy is positive, it means the reaction needs energy made available by the environment to drive the reaction. When Gibbs energy is negative, it means the reaction makes the energy it releases during the reaction available for the environment.
What determines if something will spontaneosly dissolve?
Gibbs free energy equation
Where are the Alkali Metals on the periodic table?
Group 1
Common strong acids and bases
HCl, HBr, HI, H2SO4, HNO3 (nitric acid), HClO4 (perchloric acid) NaOH, KOH, other soluble hydroxides of group 1A metals.
What is the half-equivalence point
Half the species has been protonated/deprotonated pH=pKa middle of flat part on pH graph
What is heat capacity?
Heat capacity is the product of the specific heat of an object and its mass (in grams when using c=4.184). In other words, Heat capacity = m*c
What is conductance? SI unit?
How easily electrons can flow through a substance. The higher the conductance, the easier it is for electrons to flow through the substance. Siemens (S)
What is hybridization?
Hybridization is a way of accounting for the unequal distribution of an atoms electrons within its orbitals. Essentially, an atom will mix its orbitals together based on how many bonds it has to create an overall hybridized orbital.
In liquids, what two kinds of pressures can potentially exist?
Hydrostatic pressure and osmotic pressure
How does one approach torque problems?
Identify all counterclockwise and clockwise torques and then identify all forces.
In galvanic and electrolytic cells, how do we determine what the cathode and anode are?
In galvanic, the electrode with the less positive reduction potential is the anode. Cathode is more positive reduction potential (makes sense because the one that wants the electrons is in fact getting them which is why its spontaneous) In electrolytic, the electrode with the more positive reduction potential is forced to be oxidized and is thus theanode. This is why it is non spontaneous
Describe nucleophilic acyl substitution reactions?
In nucleophilic acyl substitutions, a nucleophile attacks a carbonyl and then the carbonyl reforms, knocking off a leaving group. This is very similar to nucleophilic addition on aldehydes and ketones, but the carbonyl comes back instead of becoming a hydroxyl group. Favored in acidic and basic solutons (acidic protonates carbonyl and basic makes nucleophile better)
What is transesterification?
In transesterification, an ester is nucleophilically acyl substituted by an alcohol, which results in a different ester. This is why its called trans-esterification, because you're just changing the ester group from one to another.
What are the only ways to change the rate of a 0 order reaction
Increase temp, add catalyst
What is Infrared Spectroscopy?
Infrared Spectroscopy is a type of spectroscopy that uses IR light to measure the molecular vibrations in different moieties. In this method, IR light is passed through a sample and the amount of absorbed light is measured. Specific bonds have specific energy light associated with them, so we can use IR spectroscopy to determine the bonds in a compound.
Alternate intensity method
Intensity can be found by taking the energy density (energy per unit volume) at a point in space and multiplying it by the velocity at which the energy is moving
In which direction will a negative charge's electric field radiate?
Inward
If the oxidation half reaction has H+ and electrons on the product side, what effect will decreasing pH have on emf of the entire reaction
It will increase products and thus make it harder for the half reaction to occur, thus liberating less electrons. Emf will decrease.
Nucleophilicity/electrophilicity are (kinetic or thermodynamic properties) whereas acid base are (kinetic or thermodynamic properties)
Kinetic, thermodynamic
Angular momentum of an electron orbiting a hydrogen nucleus
L=nh/(2pi) Bohr model or (l(l+1))1/2 (h/2pi) n is principle quantum number h is plancks
What is Le Chatelier's principle?
Le Chatelier's principle states that equilibria will always oppose changes made to themselves. So, if you shift an equilibrium in one direction, the equilibrium will naturally oppose that shift and go the other direction.
Lenses [refract or reflect?] light.
Lenses refract light.
Light moves in [...]
Light moves in straight, but redirectable lines
How do we name anhydride substituents and parent chains?
Like all the carboxylic acid derivatives, anhydrides won't really ever be substituents, but in those rare cases that they are you can name them as alkanoyloxycarbonyl- When an anhydride is the parent, you must name both sides of the anhydride using the chain lengths and the -oic suffix. Place the names in alphabetical order and add "anhydride" to the end. If both sides are the same just say it once, ie butanoic acid has two butanes
What length of hydrocarbons compose micelles
Long chain fatty acids
Deviations in ideal gas law due to temperature (in regards to real gases)
Lower temp means lower speed which means intermolecular forces play a bigger role, gas takes up less volume than predicted through ideal gas law At extremely low temps, gases occupy more volume than predicted by ideal gas law (because particles can't be compressed to 0 volume)
What is mechanical advantage?
Mechanical advantage is the ratio of magnitudes of the force exerted on an object by a simple machine to the force actually applied to the simple machine.
How to estimate the equivalence point from a graph of pH
Middle of the region with the steepest slope
What is the work function of a metal
Minimum energy required to eject an electron W=hfT where fT equals threshold frequency
What is the equation for linear thermal expansion?
Mnemonic: When temperature changes, the length changes ALOT
What is Molecular Geometry and how do we predict it with VSEPR?
Molecular geometry is the geometry of the molecule as it pertains to the bonds it makes with other atoms. Because there is a distinction here between bonded electrons and nonbonded electrons, we must count them up seperately and then refer to VSEPR Theory for the shape.
Does increasing surface area of electrodes affect Keq or Ecell or current?
NO to keq and E, but it will increase current
Whats an inviscid fluid
No viscosity
What does anhydrous mean
No water
Does internal energy (of A or B) affect which substance (A or B) experiences phase changes quicker?
No, completely irrelevant
When an acid loses its proton, does the proton just float around in solution?
No, the proton is attacked by water molecules to form the hydronium ion, H3O. However, the proton still behaves as though it were free in the solution to react.
Can double and triple bonds freely rotate?
No. They are locked into place by pi orbitals.
What is noise?
Noise is defined scientifically as the sound you hear when an object vibrates at multiple frequencies that have no relation to one another.
What are non-conservative forces?
Non conservative forces dissipate energy into the form of heat/light/sound. e.g. Friction, air resistance, etc. PATH DEPENDENT
What are the general characteristics of non-metals?
Non-metals are usually brittle solids with no luster or gases. Non-metals are also poor conductors of heat and electricity.
Describe the formation of acetals or ketals from aldehydes and ketones respectively
Once a hemiacetal or hemiketal is formed, the hydroxyl group is protonated and leaves as a molecule of water, forming a carbocation (Sn1 Mechanism!!). At this point an alcohol molecule attacks, forming a ketal or an acetal depending on if the parent molecule was a ketone or an aldehyde.
What types of molecules will have largest increase in osmotic pressure
Ones that dissociate into the most particles Ex. CaCl2 would be greater than MgO
In what direction do frictional forces act?
Opposite that of the accelerating force.
Which kinds of organic compounds are likely to be colored?
Organic compounds with conjugated double bonds or aromatic ring systems.
In which direction will a positive charge's electric field radiate?
Outward
What is an oxidant and reductant?
Oxidizing agent/ reducing agent
Which takes priority in taking itΓÇÖs negative oxidation state, O or Cl
Oxygen. In NaClO, the Cl takes a plus 1
Describe the shape of a p orbital?
P orbitals are dumbell shaped.
Shortcut to getting pKa, pH, etc
P value= m-.n when in format nX10m ex. If Ka of an acid is 1.8E-5, what is pKa? 5-.18= 4.82
Ideal gas law in terms of number of molecules
PV=NkbT P in pa V in m3 N is # molecules kb is boltzmann T is temp in kelvin
What is the ideal gas law?
PV=nRT where P is the pressure , V is the volume, n is the moles of the gas, R is th ideal gas constant (.0821) and T is the temperature.
What does it mean to be paramagnetic?
Paramagnetic materials are made of atoms with unpaired electrons and net magnetic fields, but the atoms are randomly distributed and the net magnetic field within the material cancels out.
What is plane polarized light?
Plane polarized light is light in which all of the electric field vectors are lined up in one plane. Unpolarized light has random orientation of electric field vectors
How does one calculate power in terms of force?
Power = Force * Velocity * Cos(theta)
List the functional groups in terms of increasing priority.
Priority increases as you go up the list.
What conformation does cyclobutane take in order to reduce ring strain to as low as possible?
Puckered
Rate of a reaction is proportional to [overall change in energy or activation energy?]
Rate of a reaction is proportional to activation energy
What is a mixed order reaction
Rate orders that vary over the course of the reaction
How do we convert a carboxylic acid to an acyl chloride
React it with thionyl chloride. This activates the carboxylica acid
What is a broken order reaction
Reaction orders that are fractions
How does adding a resistor to a circuit affect current
Reduces overall current in it. But current at different points within new circuit is constant. So itΓÇÖs not 3A to the left of the resistor and then 2A to the right of it.
Rotating a fischer projection 90 degrees or swapping one pair of substituents will [how is the sterochemistry affected?]
Rotating a fischer projection 90 degrees or swapping one pair of substituents will invert
Describe the shape of an s-orbital.
S-orbitals are spherical shaped.
Describe a Galvanic cell
Seperate compartments called half-cells with each electrode. Each electrode is surrounded by an aqueous electrolyte solution with ions that are the same element as the respective metal electrode. Connected by wire and salt bridge.
How does wavelength affect energy
Shorter wavelength means higher energy
Sn1 reactions result in [inversion of stereochemistry or racemix mixtures?]
Sn1 reactions result in racemix mixtures This is because the carbocation is a trigonal planar intermediate, and the nucleophile can either attack it from the top or the bottom, resulting in two different stereochemistries.
How do solutes affect vapor pressure?
Solutes depress the vapor pressure.
How does one approach a projectile motion problem?
Split all motion into x and y components.
What is a stoichiometric coefficient?
Stoichiometric coefficients are the numbers we place in front of elements in a reaction to balance the reaction.
What are the four fundamental forces
Strong and weak nucelar force, electrostatic forces, gravity
How can we find the enthalpy of a reaction?
Subtract the enthalpy of the products by the enthalpy of the reactants.
What does it mean for energy in this universe to be quantized?
That the energy in this universe is quantized means that the energy only comes in discrete packets, of which you can have only whole number values. For example, energy is like children. You can either have 2 or 3, you cannot have 2.5.
What happens to the E cell of a battery as the redox reaction powering it progresses?
The E cell changes based on how far the battery is into the reaction.
The Strecker Synthesis results in a [stereoselect product or racemic mixture?]
The Strecker Synthesis results in a racemic mixture Both L and D AA can be produced
What is the axis in the context of optics?
The axis is the normal line that passes through the center of the mirror or lens.
What is the equilibrium position?
The central point around which the wave oscillates.
What is kinetic energy?
The energy an object has by virtue of its movement.
What is the nth ionization energy?
The energy required to remove the nth electron from a gaseous sample of the compound in question. For example, the first ionization energy is the energy required to remove the first electron from an atom. The 4th ionization energy is the energy required to remove the fourth electron.
What is the fundamental unit of charge?
The fundamental unit of charge is the smallest discrete unit of charge that can exist. It is the charge on the electron(negative) and the charge on the proton(positive) it is equal to 1.60*10-19C
What is the enthalpy of vaporization?
The heat of vaporizing (going from liquid to gas) at a constant pressure.
The larger the molecule, the [faster or slower?] it moves.
The larger the molecule, the slower it moves.
What happens when the vapor pressure of a liquid is equal to external pressure on the liquid (usually 1 atm, but can change depending on where you are.)
The liquid boils!
What is the phase difference between waves?
The phase difference is the extent to which the waves are offset. The higher the phase difference, the more offset the wave.
What is a dot product?
The product of the magnitudes of two vectors and the cosine of the angle between them.
What does it mean for an image to be real?
The rays of light actually converge at the position of the image.
What is the specific heat of a substance?
The specific heat of a substance is the heat energy required to raise one gram of a substance by one degree celsius or kelvin.
How can we calculate the standard enthalpy of a reaction?
The standard enthalpy of a reaction will be equal to the sum of the standard enthalpies of formation for the products minus the sum of the standard enthalpies of formation of the reactants. Remember to multiply delta H values in table by the stoichiometric modifier in the balanced equation Plug in whatever sign is in table. Keep negatives
How does one find the equivalent capacitance for capacitors in series? How do voltages behave?
The sum of the inverses will be equal to the inverse of the total capacitance. Thus, capacitors in series cause a decrease in equivalent capacitance Voltages will add up to total voltage just like resistors in series
What is an object's total mechanical energy?
The sum of the kinetic and potential energy (basically, the usable energy).
What is the work function?
The work function is the amount of energy required to knock an electron off of the surface of a metal. This is similar to but not identical to ionization energy.
What are the axes of an IR spectra?
Transmittance versus wave number.
Calculating electric potential due to a dipole
V=(kqd/r2)cos(theta) k is 9E9, q is charge of one dipole element, d is distance between dipole elements, r is point distance from dipole midpoint, theta is angle from axis of dipole Note: qd can be given as the dipole moment, p, in units called debyes (C*m)
What is vapor pressure?
Vapor pressure is the pressure associated with the gas molecules floating over an equilibrated isolated liquid.
What is velocity?
Velocity is a vector quantity that describes the change in displacement per unit of time.
Volume=Sound level (Db)=[...]
Volume=Sound level (Db)=Loudness
Equations that arise from Pascals principle
W=(F1/A1)(A1d1)=(F2/A2)(A2d2)=F1d1=F2d2
What types of molecules make good leaving groups
Weak bases (conjugate bases of strong acids)
What is nuclear fission?
When a large nucleus splits into smaller nuclei.
What is a racemic mixture and what optical activity does it have
When both enantiomers present in equal concentration, optical activity cancels out so there is no optical activity
When do we give heat positive or negative values?
When heat is entering or leaving the system, respectively.
What is rectilinear propagation
When light travels through a homogenous medium in a straight line
How does one calculate the volume and concentration of a titrated species?
Where N is the normality of the titrand and the analyte, and V is the volume of the titrand and the analyte.
How does one calculate the work done by gases?
Where P is pressure in pascals and V is volume in meters cubed.
What does the magnetic quantum number tell you?
Which orbital the electrion is in given a subshell. For example, in the p subshell there are three possible orbitals, Px, Py, and Pz. The magnetic quantum number will tell you which orbtial the electron is in.
What is the value of e
about 2.7
Describe the hydrolysis of amides
acid activated amides can be attacked by water to perform a nucleophilic acyl substitution in which ammonia is the leaving group. This requires highly acidic conditions to protonate carbonyl or strong base to increase nucleophile abilities. If in basic conditions the nucleophile would be a hydroxide which means the reaction would end with a carboxylate anion
When removing electrons, do they leave from 4S or 3D
always from the highest principle quantum number, so 4S
Movement of electrons is from ______ to ______ in an electrochemical cell
anode to cathode. Thus current is from cathode to anode. This is always the case whether it is galvonic or electrolytic
[...] creates a magnetic field
any moving charge creates a magnetic field
Organic compound
contains carbon, idiot
As high energy molecules leave the liquid and become gas the temp of the liquid _____
decreases
dehydration vs hydrolysis
dehydration- combining by taking out water hydrolysis- splitting by adding water
change in Entropy of universe is equal to
delta S system plus delta S surroundings which is greater than 0
Nonconservative work is path _____ whereas conservative work is path _____
dependent (pushing a block on asphalt), independent (gravity, electrostatics)
Negative Ecell means (electrolytic/galvanic)
electrolytic, reversing the sign would give the galvanic Ecell
What is the law of constant composition? (And other name)
example: every sample of water contains 2 H per 1 O
What is gram equivalent weight?
gram equivalent weight is the molar mass of an acid/base divided by the number of protons/OH it gives to solution.
Chalogens
group with 6 valence (oxygen)
Deviations in ideal gas law due to pressure (for real gases)
high pressure- gas molecules are close enough for inter molecular forces to play a role, Gas volume is less than whats predicted by ideal gas law At extremely high pressure, the size of the particles becomes large compared to the space between them, gas takes up larger volume than predicted by ideal gas law (gases can't be compressed to 0 volume as predicted by ideal gas law)
strength of ionic bond increases with
higher charge difference and smaller atomic radii (MgO is much stronger than NaCl)
Determining rate law algebraiclly
https://www.google.com/search?q=determining+an+overall+reaction+from+the+steps&oq=determining+an+overall+reaction+from+the+steps&aqs=chrome..69i57.7048j1j7&sourceid=chrome&ie=UTF-8#kpvalbx=1
Nsming monoatomic anions
ide ex. H- is hydride N3- is Nitride
greater kinetic energy means gases will behave more _____
ideally
CONVERT RATIO CONVERT
idiot
What is mole fraction, X?
if the give percent of each gas, assume that's the mole fraction
Treating a carboxylic acid with base will (activate/inactivate)
inactivate because it will make it a carboxylate.
In an adiabatic compression process, the internal energy of the gas
increases because work done on gas is positive. U=Q-W Q is 0 in adiabatic and W is negative because work done by the gas is neg. (compression) neg times neg equals positive
What do streamlines do
indicate the pathways followed by fluid particles as they move
What is the difference between k and Keq
k is the rate constant for the rate law equation. Keq is the equilibrium constant for the equilibrium expression.
How do you calculate Keq from k?
k of the forward reaction (kf) divided by k of the reverse reaction (kr)
What paramater defines the strength of an acid or a base?
ka or kb
What does the azimuthal quantum number represent?
l describes the subshell in which the electron resides. Each type of subshell, s, p, d, etc., has an l value.
What are the 2 process functions?
mechanical Work and Heat
What are the formulas for electric potential? How do you determine sign?
or Sign is determined by sign of source charge. Positive source will have positive V
prefix for ketone/aldehyde when not highest group
oxo- (both) keto- (ketones only)
what is p(x)?
p(x) is equal to -log(x)
Dipole moment equation
p=qd p is dipole moment q is magnitude of charge d is displacement vector separating two partial charges (distance??)
How do we convert from pH of a solution to the pOH of the solution?
pH + pOH = 14
Typical pH range for effective buffer system
pH is the pKA of the buffer plus or minus 1.
Unique things about CNMR
requires carbon 13 isotope No splitting
determining highest energy oribtals within an energy shell
s<p<d<f so in n=3 we have l=0, 1, 2 2=d so d is highest orbitals in n=3
What are electrolytes
solutes that enable solutions to carry currents , ionic compounds are electrolytes in water
Describe sp2 orbitals.
sp2 - seen in molecules with 3 areas of electron density. Results from the combination of an s orbital and 2 p orbitals. There is one p orbital left unused. This p orbital can interact with other nearby p orbitals to form a pi bond.
Describe sp3 orbitals.
sp3 - seen in atoms with 4 areas of electron density. Results from the combination of an s and all 3 p orbitals. No free p orbitals to pi bond with.
Bernoullis relation to flight
speed on top of wing greater (longer to travel up and around curved wing), so pressure lower. this means greater pressure below wing and thus lift. Big idea: Higher speed, lower pressure (higher v means the P term needs to be lower to stay equal to other side) Same applies to venturi effect
What is the equivalent weight of a compound
the mass that provides one mole of the particle of interest Interested in Hydrogen, what is equivalent weight of H2SO4? It is one half the molar mass of the compound since that will give one mole of H
what is a datum
the point that you define as 0 gravitational potential energy
Valence electrons for d and f
the s before it and then either the d or f. for 5 and 6 d dont include f before it. For example Ir has 9, 2 in s and 7 in d.
Enantiomers will have ______ IR spectra
the same
How does one calculate the energy of a photon?
where f is the frequency of the proton and h is planck's constant
When do we use molality?
BP elevation and FP depression
Converging optics have [positive or negative?] focal lengths
Converging optics have positive focal lengths
What does the 2nd law of thermodynamics state, in basic terms?
Energy will always spontaneously spread out if it is not actively being kept from doing so.
What is it called when a liquid goes to a gas?
Evaporation or Vaporization
What is flash column chromatography
Forcing the solvent through the column using gas pressure
What is GC-MS?
Gas Chromatograph-Mass Spectrometry refers to the fact that Mass Spectrometers are often hooked up to Gas Chromatographs so that, as the gaseous molecules elute separately, they can also immediately be analyzed in regards to their mass.
What kinds of reactants and products appear in the equilibrium expression?
Gases in all gas systems and aqueous molecules in aqueous systems. Solids and liquids (other than water) do not appear in the equilibrium expression.
What is displacement in the context of waves?
How far away from the equilibrium position the point on the wave is.
Hydroxly groups are [good or bad] leaving groups?
Hydroxly groups are bad leaving groups?
In a series configuration, each element will feel the same [...]
In a series configuration, each element will feel the same current
How do you quickly determine the harmonic of an open pipe?
Look at the number of nodes/ number of half wavelengths
What are common electron donating groups?
Low electronegativity substituents such as alkyls are generally electron donating due to their loosely held electron density.
What are the units of electrostatic force?
N
What are the units of Electric Field?
N/C
Indicator effect on pH
None
What does it mean to be polyvalent
One mole of acid or base liberates more than one acid or base equivalent (same a polyprotic when talking about acids)
What is the perpendicular bisector of the dipole
Perpendicular line splitting axis of dipole has 0 electric potential all along it. (cos 90 is 0)
What is the equation to calculate pressure?
Pnet=Fnet/A
What is raoult's Law?
Raoult's law mathematically describes vapor point depression. It is equal to Pa=XaPao where Pa is the vapor pressure of solvent A when solute is present, Xa is the mole fraction of solvent A in the solution, and Pao is the vapor pressure of solvent A in its pure state.
If a reaction "goes to completion" what does that mean
Reached equilibrium
What side of the reaction is heat on in an endothermic reaction?
Reactants side
What is saponification?
Saponification is the treatment of long nonpolar carboxylic acids (fatty acids) with lye to produce a salt with a nonpolar tail and a polar head. Treatment with acid will reverse this
When do we use simple distillation?
Simple distillation is used for mixtures of liquids that have boiling points below 150 C and have more than a 25 C difference in boiling point.
Describe Sn2 Reactions.
Sn2 reactions contain only one step. The nucleophile backside attacks the electrophile which simultaneously causes the leaving group to leave.
How does one calculate the magnitude of a vector from its components?
Square both component vector magnitudes, add them, and square root the sum.
Four combinations of strong and weak acids and pH result
Strong acid+strong base: HCl+NaOH->NaCl+H2O (pH=7) Strong acid + weak base: HCl+NH3->NH4Cl (pH less than 7 because NH4 will donate some proton back to water. Why wont Cl- just take it back? it is a much weaker conjugate base than NH4 is as a conjugate acid, which makes sense since HCl is a strong acid! the stronger the acid the weaker the conjugate base) Weak acid + strong base: HClO+ NaOH-> NaClO+H2O (pH is slightly more than 7 for same reasons just with ClO being a conjugate base and taking from water to produce OH-) Weak acid + weak base: HClO+NH3->NH4ClO (pH depends on Ka and Kb, whichever is larger will determine acidity. Larger Kb means greater than 7 because the conjugate base of the weak acid will be stronger than the conjugate acid of the base)
Two liquis present, what is vapor pressure?
Sum of the two individual vapor pressures
How does one calculate the work done by a gas using a P-V graph?
Take the area within the curve
What is the SI unit of pressure?
The Pascal (Pa)
What is bond energy?
The amount of energy requred to break a bond by separating its components into their isolated gaseous atomic states.
What do rows allow us to easily ascertain?
The energy level at which the element's valence electrons reside.
What do groups allow us to easily ascertain?
The number of valence electron an element has.
The oxidizing agent gets [oxidized or reduced?]
The oxidizing agent gets reduced
What is surface tension?
The phenomenon by which a liquid forms a thin but strong layer at its surface. This is caused by cohesion.
Which is the first quantum number?
The principal quantum number, n.
What is a rate determining step?
The rate determing step is the slowest step of the reaction mechanism because it acts like a kinetic bottleneck.
What is acceleration?
The rate of change of velocity m/s2
What is the reaction quotient?
The reaction quotient, Q tells you the ratio of products to reactants at some point other than equilibrium. The reaction quotient can be compared to the Equilibrium constant for a given reaction and used to determine if the reaction is going to progress forward, backwards, or stay where it is.
Of the two, which is more stable, kinetic product or thermodynamic product and why?
Thermodynamic product is the more stable of the two, more negative ΔG.
Ultimately, what determines something's solubility in a solvent?
Thermodynamics (delta G equation). If the electrostatic interactions between solvent and solute are favorable compared to the interactions between solute and solute, then the solvent will surround the solute and dissolve it.
How do the flow of electrons and current relate to one another?
They are opposite! The flow of electrons is opposite of the flow of current in an electrochemical cell.
What is the purpose of the right hand rule?
To determine the direction of the resultant vector of a cross product.
How do we convert a first order reaction into a straight line?
We graph the ln of the concentration instead of the concentration. The slope will be equal to negative 1 times the rate constant of the reaction.
Why do we need to know about effective nuclear charge?
We need to know about effective nuclear charge because inner electrons shield the outer electrons from the charge of the nucleus. This means that, even though the electrons are all being pulled upon by the same nucleus, that pull varies for each electron.
What is uniform circular motion?
When an object's instantaneous velocity vector is tangent to the circular path but centripital force (which is pointed radially inward) keeps the motion circular.
Intensity of transmitted light through a polarizer
When unpolarized light first hits a polarizer, intensity is halved (dont use cosine equation) Itransmitted = I0cos2╬╕. I0 is intensity intitial theta is angle between incident and new polarizer 90 degrees means no light is transmitted, 0 degrees means all light is transmitted
How does one calculate the modified capacitance due to a dielectric?
Where C is the original capacitance and k is the dielectric constant.
Do nonionic solutes contribute to the conductance of an electrolytic solution?
Yes, but negligibly. The concentration of the ionic solutes in the solution will always be more important than the nonionic solutes for determing conductance.
Do real gases follow the ideal gas law?
Yes, but not at all ranges. Real gases do not follow the ideal gas law at high pressures, low volumes, and low temperatures.
Reactivity towards nucleophiles
acyl halide > acid anhydride > aldehyde > ketone > ester ~ carboxylic acid > amide > carboxylate ion
pitot tubes
determine speed of fluid flow by determining difference between static and dynamic pressure of fluid at given points along tube
A voltaic cell is the same as a
galvanic cell
Calorimeters are attempts at creating
isolated systems
electrons in different orbitals with same spins are said to be
parallel
Sin(45)=
rad2/2=.707
Keq relation to being spontaneous
spontaneous if it is greater than 1, not spontaneous if it is less than 1 If Keq=1, delta G=0 and we are at equilibrium
What is the equation to calculate Gibbs Free Energy?
where G is gibbs free energy, H is the enthalpy, T is the temperature, and S is the entropy.
Rate of aA+bB->cC+dD
-(Δ[A]/aΔt)=-(Δ[B]/bΔt)=(Δ[C]/cΔt)=(Δ[D]/dΔt)
Heat of vaporization at or beyond the critical point?
0
Standard free energy for an element in its standard state
0
What is Gibbs free energy equal to at equilibrium?
0
What is the standard heat of formation for elements in their elemental form?
0
What is the vertical speed when an object reaches its maximum height?
0
What is the NMR shift associated with alkyl protons (sp3 hybridized carbons)?
0 to 3 ppm.
What is the standard enthalpy of formation of something already in a standard state?
0!
What is the reduction potentail of the standard hydrogen electrode
0V
1 formula unit is equivalent to
1 molecule ex. compare the # of molecules of 1 mol of water to the formula units in 1 mole in NaCl they are the same
Does going from energy level 1 to 2 or 5 to 6 take more energy
1 to 2 takes more than 5 to 6.
Three things to take into account for relative boiling point
1) Molecular weight. Higher molecular weight makes for a higher boiling point. 2) Intermolecular forces. More intermolecular forces, especially hydrogen bonds, increase the boiling point. 3) Branching. More branching in a moleculeΓÇÖs structure will lower its boiling point, because a lower surface area will reduce London dispersion forces.
What are the standard conditions for measuring equilibrium, kinetics, and thermodynamics problems? (signified by the degree symbol)
1. 25 degrees C or 298 K 2. 1 atm pressure 3. 1 M concentration.
What are the three guidelines with which one can assess the stability of a resonance structure?
1. A Lewis structure with small or no formal charges is more stable than a lewis structure with large formal charges. 2. A Lewis structure with less separation between opposite charges is preferred over a Lewis structure with a large sepearation of opposite charges. 3. A Lewis structure with negative formal charges on electronegative atoms is more stable than a lewis structure with negative formal charges on electropositive atoms, and vice versa.
Ranking of reactivity of caboxylic acids and their derivatives in nucleophilic substitution reactions
1. Acyl halide 2.Anhydrides 3. esters and carboxylic acids 4. amides
How are alcohols named as substituents and parent chains?
1. Alcohol substituents are given the name (hydroxy-) 2. Alcohol parent chains replace -ane with -ol.
What are some functional groups that commonly act as acids?
1. Alcohols 2. Aldehydes (at alpha carbon) 3. Ketones (at alpha carbon) 4. Carboxylic Acids (and most derivatives)
How are alkanes named as substituents and parent chains?
1. Alkane substituents are given the suffix -yl. For example, Meth-yl, Eth-yl, Prop-yl. 2. Alkane parents are given the default parent name, which is -ane. For example, Methane, Ethane, Propane.
How are alkenes named as substituents and parent chains?
1. Alkene substituents are interesting. You actually modify the parent name still, changing the -ane into -ene, but then you let the highest order functional group partially overwrite it. (3-pentene-2-ol) 2. Alkene parent chains replace the -ane of the parent name with carbon#-ene.
How are alkynes named?
1. Alkyne substituents are interesting. You actually modify the parent name still, changing the -ane into -yne, but then you let the highest order functional group partially overwrite it. 2. Alkyne parent chains replace the -ane of the parent name with the carbon#-yne.
What are the 7 general solubility rules for water?
1. All salts containing NH4+ and alkali metal cations are water soluble. 2. All salts containing NO3- and CH3COO- anions are water soluble. 3. Halides (Cl, Br, I) excluding fluorides are water soluble, with the exception of those formed with Ag+, Pb2+, Hg2+ (heavy metals) 4. All salts containing SO42- are water soluble with the exception of those formed with Ca2+, Sr2+, Ba2+, Pb2+. 5. All metal oxides are insoluble, with the exception of those formed with CaO, SrO, BaO, the alkali metals, and ammonium. 6. All hydroxies are insoluble, with the exception of those formed with Ca2+, Sr2+, Ba2+, the alkali metals, and ammonium. 7. All salts containing CO32-, PO43-, S2-, and SO32- are insoluble, with the exception of those formed with the alkali metals and ammonium
What are the five kinds of radioactive decay?
1. Alpha Decay 2. Beta minus Decay 3. Beta plus Decay 4. Gamma Decay 5. Electron Capture
Ranking of boiling points of carboxylic acid and its derivatives
1. Anhydrides (because much bigger weight) 2. carboxylic acids 3. amides (can be same or less than carboxylic acids) 4. Esters
How do you assign R and S to chiral centers?
1. Assign priority to all groups using Cahn-Ingold-Prelog 2. Rotate the molecule in 3D space such that the lowest priority group (4) is going into the page (dashed). IIf the (4) group is already on dash, you don't have to do anything! 3. Draw a circle starting from the highest priority group (1) going through (2) and (3). 4. If you drew the circle clockwise, the molecule has R configuration. If you drew the circle counterclockwise, the molecule has S configuration. This method is super effective and very fast, but it can be very hard with more complicated molecules. In those cases, it is sometimes better to represent the chiral carbon as a fischer projection and determine absolute configuration from there.
How do you assign R and S to a fischer projection?
1. Assign priority to the groups using Cahn-Ingold-Prelog Priority 2. Represent the molecule as a fischer projection. You may have to rotate the molecule to do so, remember, the arms of the molecule need to be coming out at you from where you're looking. 3. Use one of the two allowed rotations (180 degrees or anchor a carbon and rotate through the other 3) to get the lowest priority group (4) at the bottom of the cross. 4. Draw a circle from (1) through (2) to (3). If it is clockwise, then the configuration is R. If it is counter clockwise, then the configuration is S.
In general, what are good strategies for balancing equations?
1. Balance the least represented elements first and then move on to the more represented elements. 2. When you get stuck, take a guess for the coefficient of the first reactant and balance the remainder of the reaction appropriately. Afterwards, take out any common factors that are present and you will get the right balanced equation.
How are ketones named as substituents and parent chains?
1. Carbonyl substituents, whether they are aldehydes or ketones, are given the mane (oxo-) 2. Ketone parent chains replace the -e of the parent name with -one.
How do you name carboxylic acids as substituents and parent chains?
1. Carboxylic acids are the highest order functional group one would expect to see on the MCAT, so if you see a carboxylic acid it won't be a substituent, it'll be the parent. But, if there are multiple carboxylic acid groups, the substituents can be named as carboxy- 2. Carboxylic acid parents are named by replacing the -e of the parent name with -oic acid
What are factors that affect nucleophilicity?
1. Charge: Nucleophilicity increases with increasing electron density (negative charge) 2. Electronegativity: Nucleophilicity increases with decreasing electronegativity because the electrons can freely leave the atom to attack. 3. Steric Hindrance: Bulkier molecules are less nucleophilic 4. Solvent: Protic (acidic) solvents can hinder nucleophilicty by protonating the nucleophile and neutralizing its negative charge.
How do we use Huckel's rule to determine if a compound is aromatic?
1. Compound must be cyclic, not linear. 2. Compound must be planar so that the p orbitals line up. 3. The molecule must have a continuous ring of p orbitals with no sp3 carbons interrupting 4. The molecule must have 4n+2 electrons in the p orbitals where n is any whole number. (2, 6, 10, etc. not 4, 8, or 12.)
What are the 4 things that can affect the rate of a reaction?
1. Concentration of reactants 2. Temperature 3. The medium (solvent) in which the reaction takes place (generally polar solvents preferred) 4. Catalysts
What are the three types of heat transfer?
1. Conduction 2. Convection 3. Radiation
What are the two types of calorimetry?
1. Constant Pressure 2. Constant Volume
What are the various forms of isomers?
1. Constitutional Isomers 2. Stereoisomers a. Conformational Isomers b. Configurational isomers I. geometric II. optical i. enantiomers ii. diastereomers
What are the two types of equilibria?
1. Dynamic 2. Static
How do you solve for the concentration of products for a reaction given an equilibrium expression?
1. First, write the equilibrium expression for the reaction. Let's use the reaction A <> B + C for an example. 2. Second, if the reaction is 1 to 1, like this one is, the amount of reactant lost, x, will be equal to the amount of product gained, x. If the reaction is not 1 to 1, figure out how many moles of product you'd get for each mole of reactant using the stoichiometric coefficients. 3. Next, plug in the Equilibrium constant, in this example, 10-12 and the unknown concentrations of the reactants and products. 4. Finally, if Keq is more than 2 orders of magnitude less than the concentration of the reactants, then the x at the bottom of the equation can be ignored. 5. Solve for x!
What are the 5 assumptions of the kinetic molecular theory?
1. Gases are made up of particles with negligible volumes compared to the container. 2. Gas atoms exhibit no intermolecular attractions or repulsions. 3. Gas particles are in continuous random motion, undergoing collisions. 4. Collisons between gas molecules are elastic, meaning energy and momentum are conserved. 5. The average kinetic energy of gas particles is proportional to the absolute temperature of the gas (in K), and this KE is the same for all gases (As a whole, KE not the same for each individual gas particle as seen in maxwell boltzmann distribution curve), at any given temp, regardless of chemical identity.
What is the basic approach to a stoichometry problem?
1. Identify and balance the equation associated with the reaction in question. 2. Use whatever information was given (a mass, a pressure, a concentration, etc.) to get moles. 3. Use the mole ratio in the balanced equation to convert from moles of the given to moles of the required. 4. Convert from moles of required into the appropriate unit.
What are the steps for approaching a rate law chart?
1. Identify pairs of trials where one reactant is being varied while the others change. 2. Using one of the pairs of trials, see how the rate changed and compare that to how the reactant changed. 3. The relationship between these changes will give you the rate order according to the equation Xy=Z where X is the ratio of the concentrations, y is the order, and Z is the ratio of the rates. So for example, if you chose a trial where one of the reactants doubled (2x) but the rate quadrupled (4x) you would have 2y=4. And so the order would be 2
How does one name an organic molecule?
1. Identify the longest carbon chain containing the highest-order functional group. The number of carbons and the type of functional group will determine the parent name of the molecule. 2. Number the chain starting from the highest priority functional group. If the functional groups have the same priority, numbering the chain should make the numbers of any branches in the chain lowest. 3. Name the Substituents and place the names before the parent name. If there is more than one substituent of the same type, indicate it with the prefixes di, tri, etc. If there is more than one substituent of different types, place them alphabetically. 4. Assign numbers to each substituent. 5. Complete the name.
What are the characteristics of ionic compounds?
1. Ionic compounds have very high melting and boiling points. 2. Ionic compounds dissolve readily in water and other polar solvents. 3. Ionic compounds form crystalline lattice structures so as to maximize the attractive force between atoms of opposite charges and minimize the repulsive force between atoms of same-sign charges.
What are the 4 types of intermolecular forces?
1. London Dispersion Forces 2. Dipole-Dipole Interactions 3. Hydrogen Bonding 4. Ionic Bonds
What are the two criteria that a balanced equation reaction must fulfil?
1. Mass must be conserved (same number and types of elements on both sides of the equation). 2. Charge must be conserved (same overall charge on both sides of the equation).
What are the two types of geometries that VSEPR theory can give you?
1. Molecular Geometry - the shape of the molecule 2. Electronic Geometry - the distribution of electrons in a molecule NOTE: 2 different molecules can have equivalent electronic geometry but have differerent molecular geometry. This is because, although two molecules can have equivalent electronic geometry, some of those electrons might be bound to atoms in bonds while others may just be free floating as non-bonding pairs.
How does one find the overall enthalpy of a multistep reaction?
1. Note the enthalpies of each step. 2. Combine the steps in such a way so as to only express the first step and the last step. This is done by flipping equations or multiplying them by numbers so that everything except the first reactant and the last product cancel out. 3. If an equation was flipped, change the sign of its enthalpy. If an equation was multiplied by a number, multiply the enthalpy by the same number. 4. Add the enthalpies up, and you will get the enthalpy of the overall reaction.
How does one use the modified right hand rule for current in wires?
1. Point your thumb in the direction of the current. 2. Wrap your fingers around the current carrying wire. 3. Your fingers now represent the direction of the magnetic field curlng around the wire.
What are the 9 state functions?
1. Pressure (P) 2. Density 3. Temperature 4. Volume 5. Enthalpy 6. Entropy 7. Potential Energy 8. Gibbs Free Energy 9. Internal Energy
What are the Cahn-Ingold-Prelog priority rules?
1. Priority is assigned based on the atomic number of the first atom of the substituent. The higher the atomic number the higher the priority. 2. If there is a tie between the first atoms of two or more substituents, move to the next atom and use the atomic number there to break the tie. Continue as necessary. 3. Atoms that are double bonded in the substituent are counted as if there are two of those atoms bonded.\
What are the two types of Eo's?
1. Reduction Potential 2. Oxidation Potential
What are the two main types of substitution reactions?
1. Sn1 2. Sn2
What are the 4 types of newman projections (ranked in decreasing stability/ higher energy)?
1. Staggered a. Anti - Two largest groups are 180 degrees apart b. Gauche - Two largest groups are 60 degrees apart 2. Eclipsed a. Eclipsed - Two largest groups are 120 degrees apart b. Totally Eclipsed - Two largest groups are 0 degrees apart
What are the 2 important differences between static friction and kinetic friction
1. Static friction takes a range of values. Kinetic friction, on the other hand, is constant and does not depend on contact area, velocity of sliding objects, etc. ***fact check 2. The coefficient of static friction is always higher than the coefficient of kinetic friction. This means accelerating a static object takes more force than accelerating an already moving object. Furthermore, the maximum static frictional force will always be larger than the kinetic frictional force.
What are the two ways we can organically synthesize amino acids?
1. Strecker Synthesis (Strecker uses Cyanide) 2. Gabriel Synthesis (Gabriel uses Rings)
Describe the appearance of a strong acid and strong base titration curve?
1. Strong acid starts at near 0 pH. 2. Little effect on pH at low volumes of base. 2. As base volume starts to match acid volume, sharp rise. 3. Equivalence point is at 7 because a strong acid and a strong base neutralize completely. 4. As you add more base, the curve flattens out.
What three factors affect how much plane polarized light is rotated?
1. The identity of the molecule doing the rotating 2. The concentration of the molecule in the solution 3. The length of the tube through which the light is passing (more length means it hits more molecules and gets rotated more)
Describe the appearance of a weak acid and strong base titration curve?
1. Weak acid will start around a 2 pH. 2. Moderate effect on pH at low volumes because base is strong and acid is weak. 3. Sharp rise as base starts to match weak acid. 4. Equivalence point is always more than 7 because a weak acid and a strong base combine to make a slightly basic solution. 5. Curve flattens out as you add more base.
Describe the appearance of the titration curve of a weak base titrated with a strong acid?
1. Weak base starts at a 10-ish pH. 2. Moderate effect on pH as you add acid because its strong compared to the weak base. 3. Sharp drop as acid starts to match base. 4. Equivalence point is always less than 7 because a strong acid and a weak base combine to make a slightly acid solution. 5. As you add more acid, the curve flattens out.
Carboxylic acids ranked by electrophilicity and what this means
1. anyhdrides 2. carboxylic acid and esters 3. amides (worst) Higher rank can form lower rank but lower rank cant form higher rank (carboxylic acid and esters can form eachotehr)
What is weak nuclear force
1/10E6 as strong as strong nuclear force. Contributes to stability of nucleus
What is the lensmakers equation and purpose
1/f= (n-1)(1/r1-1/r2) n= index of refraction for lens material r1= radius of curvature for the first lens surface r2= radius of curvature for second lens surface This is used when the thickness of the lens is not neglidgable https://www.youtube.com/watch?v=vnAn3ON5O3M Remember, to obtain the signs of radius 1 and 2 looks at the first surface the lens passes through and then the second. The side with observer is considered pos. So if observer was on left then first surface would be pos because radius goes to left. Second surface would be neg
Solve 100x=1000
102x=103 2x=3 x=1.5
What are the ideal bond angles for a carbon with four bonds (sp3)?
109.5 degrees
Say we have a 10V battery, from the positive terminal to the negative terminal (around the circuit), the voltage drop will be ______ and from the negative terminal to the positive terminal (through the battery) the voltage change will be ______
10V for both! all voltage is lost going around circuit and then gained again when traversing battery. Thus, from positive terminal all the way around to positive terminal, the voltage change will be 0V. But from positive to negative terminal, the voltage change will be -10V. Makes sense with regards to loop rule, voltage gained+voltage lost=0
What is Faradays constant
1F=96, 485 C/mol e- Basically one F is equivalent to the amount of charge in one mol of electrons On test use 105 C/mol e-
Vapor pressure of water at 100 degrees celsius
1atm idiot
Molecular orbitals contain a maximum of ____ electrons
2, like any orbital
When light passes between mediums with two different indexes of refraction, how many beams of light are created
2, one is reflected back into source medium and one is refracted into new medium. In special cases when going from high n to low n, and the critical angle is exceeded, all light will appear reflected (because the refraction angle is higher than 90 and thus goes back into original medium)
What is the shape of the P orbital?
3 lobes that share a center but extend across three different axes.
2pi rads in degrees
360 degrees. Dont get confused with radians as units. A radian isnt equal to 2pi, it just get thrown in after the 2pi. Aka 1 rad isnt equal to 360 degrees, 2pi rads is equal to 360 degrees
What is the most bonds a carbon will ever have in an organic molecule?
4! This helps us fill in the hydrogens of line angle structures. For example, if there are already two bonds to a carbon, you know the other two substituents are the undrawn hydrogens. Note, there are carbocations and other such specific cases when carbons will have less than 4 bonds, but you will learn about these and recognize them going forward.
What is the value and units of Coulomb's constant?
9.0*109 (N*m2)/C2
How does one convert from atm to mmHg or torr to pascals to bar?
=1.013bar=1.013E5pascals
What is the equation for the distances of objects and images in optics?
=2/r where f is the focal length, o is the length at which the actual object is, and i is the length at which the image of the object is. NOTE: Different types of optics will have different sign conventions. It's extremely important you remember the sign
How does one relate standard gibbs free energy of a reaction and non standard gibbs free energy of a reaction?
=RTln(Q/Keq) (if Q/Keq is less than 1 then ln(Q/Keq) will be neg making all free energy neg making it spontaneous and viceversa) where R is the ideal gas constant 8.314 and Q is the reaction quotient of the reaction (concentration of products raised to th
What is a backside attack?
A backside attack is the way nucleophiles attack electrophiles in Sn2 reactions. They always attack this way because it is lower energy than attacking from the front (where there is more stuff in the way). Backside attacks are interesting in that they invert the configuration of the molecule when they occur. What happens to a molecule during a backside attack is similar to what happens to an umbrella when the wind blows it inside out.
What is a beta dicarboxylic acid?
A beta dicarboxylic acid is a dioic acid with 1 carbon in between the carbonyls. These molecules are interesting because their alpha hydrogen is also pretty acidic. Remember, this phenomenon is seen in any 1,3- dicarbonyl compound.
What is an example of a constant volume calorimeter?
A bomb calorimeter is a contstant volume calorimeter. The vessel is rigid and its volume does not change during the chemical reactiion.
What is a bonding orbital?
A bonding orbital is a molecular orbital where the two atomic orbitals overlapping have the same sign, and therefore add up to a higher magnitude orbital.
What is a buffer solution?
A buffer solution is a mixture of a weak acid and it's conjugate base. (The conjugate base is usually added to the solution in the form of a dissociable salt. This means there will be a random cation on the conjugate base).
What is a capacitor?
A capacitor is an electrical element that can store energy within itself.
What is a carbaldehyde?
A carbaldehyde is the suffix given to an aldehyde on a ring system
What is a carbanion?
A carbanion is a carbon atom with a lone pair and a negative charge. Carbanions are very unstable and need to be stabilized if they're going to last for any meaningful amount of time.
What is a carbonyl group?
A carbonyl group is a carbon double bonded to an oxygen.
What is a carboxylic acid?
A carboxylic acid is a molecule with a highest order functional group of a terminal carbonyl with an -OH group.
What is a catalyst?
A catalyst is something that lowers the activation energy of a reaction without being used up in the reaction.
What is a cathode?
A cathode is where reduction occurs.
What is a chair flip and how does it affect the molecules conformation?
A chair flip is when one chair form converts to the other possible form. In a chair flip, the cyclohexane briefly passes through a fourth conformation called the half-chair conformation. After the chair flip is complete, the cyclohexane molecule will still be in chair conformation, but all the axial bonds will now be equatorial and all the equatorial bonds will be axial. However, the components that were facing "up" are still facing "up" and the components facing "down" are still facing "down".
What does it mean for protons to be chemically equivalent?
A chemically equivalent proton is a proton that is attached to the same atom and surrounded by the same atoms. The NMR can't really tell the difference between chemically equivalent protons, and so they will have the same chemical shift value. However, the more protons, the higher the absorbance (height of the peak) at that chemical shift.
What is a closed boundary?
A closed boundary is a boundary that does not allow oscillation, and therefore corresponds to a node. A string tied to a brick wall would be a good example of a closed boundary. Also the closed end of a pipe
What is a closed pipe?
A closed pipe is a pipe that is closed at one end and open at the other end, so one end supports a node and the other end supports an antinode.
What is a closed system?
A closed system is one in which energy can be exchanged, but matter cannot. (ex. pistons)
What is an example of a constant pressure calorimeter?
A coffee cup calorimater is a constant pressure calorimeter. The incident pressure is atmospheric pressure, and the pressure is constant throughout the reaction.
What is the archetypal form of the combination reaction?
A combination reaction is when two or more reactants come together to make 1 new product.
What is the archetypal form of the combustion reaction?
A combustion reaction is when a fuel is oxidized to create CO2 and H2O. The fuel will almost always be a hydrocarbon of some sort. The oxidizing agent will almost always be Oxygen.
What is a complete ionic equation?
A complete ionic equation shows a reaction with all of the aqueous reactants and products written as their dissociated ions. Keep solids intact
When will a concave meniscus form?
A concave meniscus forms when the adhesive forces of the liquid are greater than the cohesive forces (the liquid prefers sticking to the wall than to sticking to itself.)
What is a condensation reaction?
A condensation reaction is a reaction where two molecules are joined with the loss of a small molecule.
What is a conductor?
A conductor is any material that distributes charge over its surface and transfers charges well. Most metals are conductors. Ionic solutions are also effective conductors. electrons move easily and not as closely associated with nuclei as in insulator
What is a configurational isomer?
A configurational isomer is a molecule that differs in its 3D orientation in such a way that it can't just rotate around the bond to interconvert, like a conformational isomer. Bonds would need to be broken to interconvert. This is seen in double bonds and stereocenters.
What is a conjugate acid?
A conjugate acid is the acid formed when a base picks up a proton from some other acid.
What is a coordinate covalent bond?
A coordinate covalent bond is when one atom contributes both of the electrons that the atoms will share to form their covalent bond. When given a molecule, consider how it was formed. Ex. how many coordinate bonds in NH4+? We know that NH3 has one lone pair so to make NH4+ that lone pair would contribute both electrons to an H+. It wouldnt split the lone pair with a regular H to make a nitrogen with a free radical
What is a coordination compound and what type of bond allows them to form?
A coordination compound, a.k.a, a complex ion refers to a molecule in which a cation is bonded to at least one electron pair donor (called ligands). This electron pair donor is often the solvent, like water. Held together through coordinate covalent bonds
What is a crystal lattice?
A crystal lattice is the way the atoms of an ionic bond will situate themselves in a group so as to minimize the energy of the system and stabilize the compound.
What is a diastereomer?
A diastereomer is a molecule that is non-super imposable but is not a mirror image of another molecule. This can only really happen when there are more than one chiral centers, so it's a good idea to be thinking about diastereorism whenever you see multiple chiral carbons in a molecule.
what is a -dioic acid? Common names?
A dioic acid is a molecule with carboxylic acid groups on both ends of the molecule. They are named by adding -dioic adic to the parent name.
What is chromatic aberration
A dipersive effect within a spherical lens. Depending on the thickness and curvature of the lens, there may be significant splitting of the white light, which results in a rainbow halo aroind the images. This can be corrected for with special coatings with different dispersive qualities.
What is a galvanic (voltaic) cell?
A galvanic (or voltaic!) cell is an electrochemical cell in which electrons are going from low reduction potential to high (anode to cathode), and releasing energy.
What is a group in regards to the periodic table?
A group is a vertical column on the periodic table.
What is a heating curve?
A heating curve is a graph of temperature versus heat added.
What is a heterogenous catalyst?
A heterogenous catalyst is a catalyst that is in a different phase (solid, liquid, gas) than the reactants.
What is a hydrazone?
A hydrazone is a modified version of an Imine. In this molecule, the double bonded nitrogen has a nitrogen attached.
What is a ketone?
A ketone is a molecule with a carbonyl somewhere inside the carbon chain, not at the end.
What is a lactam?
A lactam is an amide in a cyclic system. They are often named by indicating the greek carbon that was attacked in the cyclization of the molecule.
What is a ligand?
A ligand is the electron pair donor molecule that attaches to the electron accepting core.
What is an equipotential line?
A line on which the potential at every point is the same. always perpendicular to field lines
What is a meso compound?
A meso compound is a compound that has chiral centers, but doesn't exhibit optical activity. This is only possible in molecules that have internal planes of symmetry, which just means you can cut the molecule into two identical halves some how. has a superimposable mirror image L and D will show optical activity, but the meso- compound below won't. https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Chirality/Meso_Compounds
What is a mixture?
A mixture is some combination of two things, whether or not it is homogenous or heterogenous.
What is a mole?
A mole is a unit we made to conveniently describe the quantity of chemical quantities. One mole is equal to 6.02*10^23 of whatever substance is in question. You could have a mole of cats in the same way you have a dozen eggs. One mole of cat is 6.02*10^23 cats and one dozen of eggs is 12 eggs.
What is a molecular orbital?
A molecular orbital is like an atomic orbital (the area of space where electrons can be found) but for a molecule instead of an atom. Areas of overlap between the atomic orbitals that make up the molecular orbital correspond to bonds in the molecule.
What is a molecular orbital?
A molecular orbital is like an atomic orbital (the area of space where electrons can be found) but for a molecule instead of an atom. Areas of overlap between the atomic orbitals that make up the molecular orbital correspond to bonds in the molecule. top: bonding orbital bottom: antibonding orbital
What is a net ionic equation?
A net ionic equation is the complete ionic equation minus the spectator ions.
What is a newman projection?
A newman projection is a way of looking at molecules to better understand conformational isomerism. In this projection, one looks down the bond and represents the substituents of the front and back carbons with lines to the appropriate groups.
What is a nitrile?
A nitrile is a carbon triple bonded to nitrogen. This is usually a result of a reaction with Cyanide (C triple bonded to N). Cyanide below
Explain why plane mirrors always make virtual images.
A plane mirror is defined as a flat reflective surface. That means that the light rays will always just bounce off of the mirror with the same angle they bounced onto it with (parallel rays wil enter and leave parallel) This means that the light rays don't ever converge, they just get reflected away. Any light we see is just being bounced off the mirror, but our brains are used to tracing light back to its source, so what will happen is instead of really seeing the reflection, our brain treats the reflected rays as if they came from an imaginary source and traces them back to said source. This is why when we look into a mirror, it's like there is a person looking back at us from the other side of the mirror. Our brain thinks that is where the light is coming from. Because the light is actually converging on our side of the mirror, and not where we perceive the image to be, this is a virtual image.
A positive oxidation potential means the molecule wants to be [reduced or oxidized?]
A positive oxidation potential means the molecule wants to be oxidized
A positive reduction potential means the molecule wants to be [reduced or oxidized?]
A positive reduction potential means the molecule wants to be reduced
A positive standard potential means the reaction is [favorable or nonfavorable?]
A positive standard potential means the reaction is favorable and spontaneous
What is a process function?
A process function is a thermodynamic property that is a function of the path taken to a certain state.
What is a reduction potential?
A reduction potential is the potential change associated with a reduction reaction. How much something wants to be reduced (more positive means more likely to be reduced)
What is a resonance structure?
A resonance structure is a lewis structure that has the same bond connectivity as another lewis structure for the same molecule, it's just that the electrons are arranged differently. Remember, bonds are made of electrons, so the bond orders can change as well. The arrangement of atoms cannot. if the arrangement of atoms is different, the molecule is a constitutional isomer, not a resonance structure.
What does it mean to be a saturated solution?
A saturated solution is a solution that has the maximum amount of dissolved ions as defined by the ksp. Any solute added to a saturated solution will precipitate.
What is density?
A scalar quantity that describes how much mass is packed into each unit of volume for a given substance.
Describe the graph of a second order reaction
A second order reaction means that the reaction is dependent on the square of 1 reactant or dependent on the product of two reactants. At the start of the reaction there are a lot of reactants, and the reaction goes very fast. This causes the amount of reactants to plummet as they are converted into products. This can be seen on the graph as a steep line downwards at the start of the reaction. As the reaction progresses and there are less reactants, the reaction slows down. This causes the steep dive of the reactants to flatten out, similar to a first order reaction. A second order reaction is just like a first order reaction, it just dives steeper at first and flattens out sooner.
What is a semicarbazone?
A semicarbazone is a modified version of an Imine. In this molecule, the double bonded nitrogen has a N-C(O)-N moiety attached.
What kind of bonds make up a double bond?
A sigma bond and a pi bond perpendicular to the axis of the sigma bond.
What is a sigma bond?
A sigma bond is a molecular orbital formed by the head-to-head or tail-to-tail overlap of two atomic orbitals. note: sigma bonds can bet between atomic orbitals of any type, not just s orbitals.
What is a solution?
A solution is a homogeneous mixture of two or more substances in a single phase (usually liquid).
How do we know if something is not a spectator ion?
A species is defined as a non-spectator when it's oxidation number or it's physical state (gas, solid, liquid, etc.) changes.
What is a standing wave?
A standing wave is a wave that appears to be stationary because of the interference pattern of the two waves that make it. The only apparent movement of a standing wave will be the fluctuation of the amplitude of the wave. Standing waves can only be observed in closed end wave systems. The gif below illustrates. The top wave is the incident wave, the middle wave shows the reflected wave, and the bottom wave shows the superposition wave of the top and middle wave.
What is a state function?
A state function is a thermodynamic property that is a function of only the current equilibrium state, not the path that was taken there.
What is a stereoisomer?
A stereoisomer is a molecule with the same chemical formula and the same connections of atoms, but in different spatial arrangements.
What is a stereospecific reaction?
A stereospecific reaction is a reaction that produces a specific stereoisomer, not a racemix mixture.
What does it mean to be a strong acid?
A strong acid is an acid with a high Ka value that dissociates completely.
What is a structural isomer?
A structural isomer (aka constitutional isomer) is a molecule with entirely different bonding and arrangement, it just happens to have the same molecular formula. Molecular formula for the below molecules are all C4H9Br
What does it mean to be an supersaturated solution?
A supersaturated solution is a solution in which the Ion product of the ions is higher than the ksp. Normally this wouldn't be possible, but with special treatment it can be achieved. First, you saturate a solution, so it's IP = ksp and adding anymore solute will cause precipitation. Then, you heat the solution, so it's ksp increases. You can now add some solute again until you reach the new ksp. Once you've added solute and reached the new ksp, you slowly cool the reaction, lowering the ksp. If you're careful, the extra solute you added will not precipitate and will instead remain suspended in solution. This means that the IP is greater than the Ksp!
What is a trough?
A trough is the lowest point a wave reaches.
What does a voltmeter measure?
A voltmeter measures the voltage between two points in a circuit. Measure magnetic properties like ameter. Wired in parallel to the two points it is measuring and has infinite resistence. Circuit needss to be on
Describe the hydration of aldehydes and ketones.
A water molecule attacks the carbonyl carbon, popping the double bonded electrons up onto the oxygen. The oxygen then takes the extra proton from the attached water molecule, forming a geminal diol. This reaction proceeds slowly, and it can be sped up by adding a small amount of catalytic base or acid.
Describe the graph of a zeroth order reaction?
A zeroth order reaction means the rate of the reaction is independent of the concentration of the reactants. rate=k[A]0[B]0=k Therefore, the rate of the reaction is constant, and the reactants will be used up over time at a constant rate. I.e. a straight line. k= (-1)slope
How do you calculate the atomic weight of an atom with two naturally occurring isotopes?
A*X + B*Y = Atomic Weight A is equal to the mass number of the first isotope. X is equal to the percentage prevelance of that first isotope. B is equal to the mass number of the second isotope. Y is equal to the percentage prevelance of that second isotope.
How much mass does an electron add to an atom?
About 1/2000th of a proton. Essentially the mass of an electron is negligible in its contribution to the mass of an atom.
What is achirality?
Achiral molecules are molecules that have mirror images that can be superimposed on one another.
How are acid anyhdrides usually formed?
Acid Anhydrides are normally created from the condensation reaction of two carboxylic acids.
How does acid affect every acyl substitution reaction?
Acid will protonate the carbonyl oxygen, making the carbonyl carbon an even better electrophile and pushing the reaction forward. In most acyl substitutions, the acid is just a catalyst. However, if the nucleophile being used is very weak, activating the carbonyl oxygen with acid is a necessary step to get the reaction to happen at all.
What is activation energy?
Activation energy, Ea is the amount of energy it takes to start a reaction between two molecules. This energy is supplied by temperature (more kinetic energy) and orientation (when the molecules hit in a certain way it can generate more or less energy).
What is an acyl derivative?
Acyl derivatives are all molecules with a carboxylic acid derived carbonyl. So this means that the nucleophilic acyl substitution mechanism applies to Carboxylic Adcids, Amides, Esters, Anhydrides, etc.
How can you increase the frequency factor of a reaction?
Add more molecules.
How do we get the molecular weight of a molecule?
Add the atomic weights of the elements that make the molecule up. Remember, we can always refer to a periodic table for the atomic weight of any element.
How does one calculate the equivalent capacitance of capacitors in parallel? How do voltages behave?
Add up the individual capacitances. Thus, capacitors in parallel causes an increase in equivalent capacitance Each voltage is the same and equal to the source voltage
Calculating total osmolarity and what it represents in osmolarity problems
Add up the moles of every particle in solution So if we disolve 2mol NaCl, our solution will have 2 mol Na and 2 Mol Cl, making total osmolarity 4 osm. If we have mOsm, divide by 1000 to get Osm or mole/L. If total osmolarity is given it represents iM in the osmolarity equation because it already accounted for i
What does a carboxylase do
Adds a CO2
What are characteristic physical properties of alcohols?
Alcohols, because of their -OH moiety, can participate in hydrogen bonding. This results in alcohols having very strong intermolecular forces, and thus higher melting and boiling points. The more -OH's, the stronger the hydrogen bonding. Alcohols are also polar, and dissolve well in water.
Describe the reduction of aldehydes and ketones?
Aldehydes and ketones, when combined with reducing agents such as LiAlH4 and NaBH4, are reduced to alcohols (less bonds to oxygen!). Look for hydrides bound to metal ions
Describe the formation of hemiacetals or hemiketals from aldehydes and ketones respectively?
Aldehydes treated with one equivalent of alcohol will produce hemiacetals. In this reaction, the alcohol acts as a nucleophile and attacks the electrophile carbonyl carbon. The electrons pop up to the oxygen, and the oxygen picks up the alcohol's hydrogen, resulting in a hemiacetal. *This reaction can be catalyzed with acid which will protonate the carbonyl oxygen and make the carbonyl carbon a better electrophile.* not sure about this The formation of hemiketals from hemiacetals is exactly the same, except there will be R groups on both sides of the carbonyl carbon, not just one.
All L-amino acids have (S) configurations except for [which amino acid?]
All L-amino acids have (S) configurations except for cysteine This is becasue the Sulfur in Cysteine's side chain flips its priority around. Try it yourself!
Are objects ever virtual?
Almost never on the MCAT (even if it is on the "virtual" side of the lens, the object is still real) The only scenario is when the image of one lens becomes the object of another
How do the penetrating powers of Alpha, Beta, and Gamma decay compare?
Alpha Particles penetrate very little, Beta Particles penetrate a modest amount, and Gamma Rays penetrate the most.
Which form of radiation is most dangerous if its source is inside the body?
Alpha decay is the most dangerous radiation if its occuring inside the body. This is because the alpha particle is not very penetrating, and won't be able to break out of the body. These particles will just stay in the body doing damage. A gamma ray, though higher energy, will exit the body very quickly due to its penetrance.
What is an alpha hydrogen?
Alpha hydrogens are hydrogens that are attached to an alpha carbon (one away from the carbonyl). These hydrogens are of above average acidity because the conjugate base can be resonance stabilized.
Free energy and Ecell sign relation
Always opposite
Describe the characteristic properties of an amide bond.
Amide bonds undergo resonance stabilization between the carbonyl and the lone pair on the nitrogen. This stabilizes the bond nicely, locks it into place (no free rotation) and makes it very difficult to break. It's a good thing our amino acids are linked by these bonds because otherwise our proteins would just fall apart and twist around wildly.
Amides, Esters, and anhydrides are produced from by [] reactions?
Amides, Esters, and anhydrides are produced from by condensation reactions? Remember, these molecules are produced by bringing together two molecules and losing a small one, in the case of these reactions,the small molecule lost is water.
What does an ammeter measure?
Ammeters measure current at some point in the circuit. Use the magnetic properties of current carrying wire to obtain a measurement. has extremely low resistence as to not change circcuit mathematics when inserted into circuit (increasing resistence would decrease current). Inserted in series into the circuit. Circuit needs to be on
What does Faraday's Law state
Amount of chemical change induced in an electrolytic cell is directly proportional to the number of moles of electrons that are exchanged during the reaction.
What are the SI units of current?
Amperes
What is an MRI?
An MRI is just applying NMR to humans. Using NMR, we can determine the density of hydrogens in the body, which correspond to tissue types. More hydrogens= brighter. so lots of water or fat =brighter. so bone=dark DONT NEED TO KNOW THESE DETAILS By looking at the general shape of tissues and cavities in the body, we can determine abnormalities.
What is an absorption spectrum?
An absorption spectrum is like the atomic emission spectrum, only instead of cataloguing the photons that are emitted when excited electrons fall, absorption spectra catalogue the photons that are absorbed when ground state electrons are promoted to excited states. Remember, the difference in energy going from energy level 1 to 2 is the same amount of energy as going from energy level 2 to 1, so the photons emitted by the emission spectrum are the same photons absorbed in the absorption spectrum.
What does it mean to be adiabatic and how does that affect the first law of thermodynamics equation?
An adiabatic process is one in which there is no change in heat. W is negative for my version change in internal energy of the system is equal to work done on the system
What is an alcohol?
An alcohol is a molecule with a highest priority functional group of an -OH.
What is an aldehyde?
An aldehyde is a molecule with a carbonyl at the end of the carbon chain.
What is a-racemization?
An aldehyde or ketone with a chiral alpha carbon will rapidly become a racemic mixture due to keto-enol tautomerization. Keto-enol tautomerization is non-stereospecific, so it will just randomly convert stereoisomers back and forth, generating a racemic mixture.
What is an alkane?
An alkane is an organic molecule with a highest priority functional group of a Carbon - Hydrogen bond. Note, this is basically the default for organic molecules, and so it follows that alkanes are the absolute lowest priority functional group.
What is an alkene?
An alkene is a molecule with a double bond.
What is an alkoxy group?
An alkoxy group is a carbon moiety that is attached to the parent chain through an oxygen bond.
What is an alkyl halide and how are they named?
An alkyl halide is a halogen bound to a normal carbon (not a functional group of import). Alkyl halides are always substituents and are named by adding an -o to to their root element name.
What is an alkyne?
An alkyne is a molecule with a triple bond.
What is an Amide?
An amide is a carbonyl carbon bonded to a nitrogen.
What is an aminonitrile?
An amino nitrile is a molecule with an amino group and a nitrile group
What does it mean to be amphoteric?
An amphoteric substance is something that can react like an acid or a base. Water is amphoteric.
What is an anode?
An anode is where oxidation occurs.
What is an antibonding orbital?
An antibonding orbital is a molecular orbital where the two atomic orbitals overlapping have opposite signs and cancel out when they combine.
What is an antinode?
An antinode is any point on a standing wave where interference is maximized and the amplitude is greatest.
What is an aqueous solution?
An aqueous solution is any solution in which the solvent is water.
What is an aromatic compound?
An aromatic compound is a conjugated ring system that follows Huckel's Rules. These compounds are very stable!
What is the definition of an arrhenius base?
An arrhenius base is something that dissociates to form an OH- ion.
What does it mean for an atom to be in ground state?
An atom is in ground state when all of its electrons are in the lowest possible energy shells they can occupy.
What is meant by primary, secondary, tertiary, and quaternary in the context of organic chemistry?
An atom is said to be primary, secondary, tertiary, or quaternary based on the number of carbons to which it is bound.
What is an atom's mass number?
An atom's number is equal to the number of protons plus the number of neutrons in the nucleus. Essentially, mass number is equal to the total mass of the atom (because electrons give so little mass they are not accounted for.)
What is an atomic emission spectrum?
An atomic emission spectrum is a cataloguing of all the electron transitions an atom can undergo and the photons those transitions release. Remember, the distances between energy levels are different in every atom. Therefore, the photons released when an electron falls from an excited state to ground state are different in every atom. We can use the photons an atom releases to determine its identity.
Describe the diversity of electrochemical cells.
An electrochemical cell can be made out of almost anything, as long as there is a cathode and an anode of some sort connected by something. This is seen in batteries as solution reactions connected by wires, but it can be seen in the body as two sides of the mitochondria connected by a plasma membrane. As long as there is flow of electrons, there is potentially an electrochemical cell at play.
What is an electrochemical cell?
An electrochemical cell is an anode and a cathode connected somehow that captures the flow of electrons to harness energy.
What is an electrolytic cell?
An electrolytic cell is an electrochemical cell in which electrons are going from high reduction potential to low (still anode to cathode), and this requires the input of energy.
What is an electrolytic solution?
An electrolytic solution is a solution with dissolved ions. These solutions can conduct electricity through themselves.
What is an electron configuration?
An electron configuration is a shorthand accounting of the electrons in an atom using s,p,d,f notation.
What is an electrophile?
An electrophile is an atom that is attracted to the negative charge of the electrons on other atoms. Generally electrophiles have a positive charge or are in a dipole-dipole bond that gives them a partial positive charge. (aka alcohols, aldehydes, ketones, carboxylic acids and most of their derivatives) Good leaving groups make electrophiles good as well
What is empirical formula?
An emprical formula is the most-reduced whole number ratio of the atoms in the compound. ionic compounds only have empirical (NaCl)
What is an enamine?
An enamine is the tautomer of Imines. It is a carbon double bond with an amino group attached. Like enols, enamines are the less common form
What is an ideal gas?
An ideal gas is the hypothetical gas described in the ideal gas law. It refers to a gas that has 0 volume and 0 intermolecular forces. As the molecules in the gas get bigger and as they exhibit stronger intermolecular forces, they behave less ideally.
What does it mean for an image to be virtual?
An image is virtual if the light appears to be coming from the position of the image, but the light rays don't actually converge there.
What is an imine
An imine (/ɪˈmiːn/ or /ˈɪmɪn/) is a functional group or chemical compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen (H) or an organic group (R). If this group is not a hydrogen atom, then the compound can sometimes be referred to as a Schiff base.
What is an indicator?
An indicator is a molecule that changes color with changes in acidity/basicity. This is what we use to determine when the endpoint of an acid base titration has been reached.
What is an insulator?
An insulator is any material that will not easily distribute a charge over its surface. Most nonmetals are insulators. Molecularly, electrons are closelely linked to nuclei
What is an ionic bond?
An ionic bond is when one or more electrons from one atom are transferred to a different atom. This is usually how metals and nonmetals bond, because metals really want to get rid of a few electrons and nonmetals really want to gain a few electrons. Form crystal lattices where each molecule is attracted to many others
What is an irreversible reaction?
An irreversible reaction is a reaction that goes forward to completion, and makes the full amount of product possible given its reactants.
What does it mean to be isochoric(isovolumetric) and how does that affect the first law of thermodynamics equation?
An isochoric process is one in which no change in volume occurs. Without volume change (compression or expansion) there can be no work. change in internal energy is equal to the heat added
What is Newton's First Law?
An object at rest or in motion with constant velocity will remain that way unless a force acts on it.
What are translational and rotational equilibrium and how do they relate to electric dipoles
An object is at translational equilibrium if the net linear acceleration of its centre of mass is 0. Its centre of mass could be movingΓÇöit would just be moving at constant speed. Since F = ma, this also implies that the net force acting through its centre of mass is 0. The word ΓÇÿtranslationalΓÇÖ is used to distinguish translational from rotational equilibrium, which means that its net angular acceleration is 0. An object can be at translational equilibriumΓÇöi.e. its centre of mass would be travelling at constant velocityΓÇöbut also rotating about its centre of mass with changing angular velocity. In this case, it would be at translational but not at rotational equilibrium. DIPOLE at some angle with electric field has translational eq but not rotational eq
What is an open boundary?
An open boundary is a boundary that allows maximum oscillation because it really isn't a boundary. Examples of an open boundary are the free end of a flag and the open end of a pipe.
What is an open pipe?
An open pipe is a pipe that is open at both ends, and so both ends of the pipe support anti nodes.
What is an open system?
An open system is one in which both matter and energy can be exchanged with the surroundings. (ex. boiling pot of water, humans)
What is an optical isomer?
An optical isomer is an isomer that changes the way the molecule rotates plane-polarized light. Enantiomers and Diasteromers are both considered optical isomers.
What is an Oxidation-Reduction (Redox) reaction?
An oxidation-reduction reaction is a reaction that involves the transfer of electrons.
What is angle strain?
Angle strain is the strain introduced into a molecule whenever bond angles deviate from ideal. This strain makes the molecule less stable.
What is angular frequency?
Angular Frequency is a measurement of how many radians (2pi radians is 1 full circle) a wave rotates per second. This is just another way of thinking about frequency. Although it is a little harder to visualize, thinking about frequency in this way is useful for certain situations. If you want to convert 2Hz to angular frequency, it would be 4pi rads per second. A common misconception is that a radian is equal to 2pi so you divide your answer by 2pi to get radians per second (2 rads per second). Dont do this. In the above example, the wave rotates a full circle (2 pi radians) in 2 seconds.
What is an anhydride?
Anhydrides are molecules with two carbonyls bonded to the same oxygen. (know acetic anhydride)
Describe the cleavage of anhydrides.
Anhydrides can be cleaved with various nucleophiles using the standard nucleophilic acyl substitution mechanism. Note alcohols can do this too (which will result in the formation of esters and carboxylic acids). Waters can also split into two carboxylic acids
Anti Bonding orbitals are [higher or lower energy?] than bonding orbitals
Anti Bonding orbitals are higher than bonding orbitals This also means they are less stable! Atoms together are higher energy than the atoms apart
What is Pascal's Principle?
Any change in pressure in a fluid will be transmitted undiminished to every portion of the fluid and to the walls of the containing vessel.
What changes to an acid will make it stronger?
Any change that stabilizes the conjugate base. This is usually due to induction. Example shown below.
How big must the difference in electronegativity be to be considered a polar bond?
Any electronegativity difference between 0.5 or 1.7 will seperate charge enough to create a polar bond.
What is the second law of thermodynamics?
Any given process must result in an increase in total entropy in the universe. In other words, things cannot go from disordered to more ordered spontaneously. For a specific example, consider heat. Heat will not flow from a cold object to a hot object, decreasing entropy. Instead, heat will always from a hot object to a cold object in thermal contact until the temperatures of the objects are equal and the entropy of the universe is higher.
What are the possible values for n?
Any positive integer to infinity (whole number other than 0).
How big must the difference in electronegativity be to be considered an ionic bond?
Any two elements with an electronegativity difference of greater than 1.7 will form an ionic bond. This is because the difference in electronegativity is so big that one of the atoms just takes the electrons from the other one instead of sharing them.
What is the formula for Ohm's Law?
Applies to a single resistor, any part of a circuit, or the entire circuit (assuming you calcualte the equivalent resistence from a resistors in the circuit)
In a reaction with two possible products, how do you get the thermodynamic product?
Apply a higher temperature to the reaction.
In a reaction with two possible products, how do you get the kinetic product?
Apply low temperature to the reaction.
What is Archimedes' principle
Archimedes' principle states that an object in a fluid will be pushed upwards by a force that is equal to the weight of the fluid it displaces.
As Intensity goes up volume [...]
As Intensity goes up volume increases
As frequency increases, pitch [...]
As frequency increases, pitch increases
As intensity of a stimulus goes up action potential [frequency or magnitude?] increases
As intensity of a stimulus goes up action potential frequency increases
As one goes right and up across the periodic table effective nuclear charge [...]
As one goes right and up across the periodic table effective nuclear charge increases
As principle energy level goes up, the electron's radius from the nucleus [...].
As principle energy level goes up, the electron's radius from the nucleus increases.
Describe the relative energies of the newman conformations
As shown below, the 2 anti-staggered configurations @ A and G are lowest energy and most stable (least steric hindrance). Next in terms of energy are the two gauche configurations @ C and E Next in terms of energy are the two eclipsed configurations @ B and F Finally, the highest energy conformation is the totally eclipsed configuration, which can only manifest itself one way, as seen @ D.
As temperature increases, a resistor's resistance will [...]
As temperature increases, a resistor's resistance will increase Note: glass, pure silicon, and most semiconductors
What is the purpose of a salt bridge?
As the cathode gets more and more electrons, it starts to build up a negative charge. The anode starts to build up a positive charge as it loses electrons as well. As the anode and cathode diverge from their original charges, the reaction becomes less efficient and progresses less vigorously. The salt bridge fixes this problem. The bridge is filled with inert ions that will affect the charge of the solution without reacting with the redox-reaction. The cations in the salt bridge will go to the cathode to cancel out the negative charge build up, and the anions will go to the anode to cancel out the positive charge build up.
As the charge separation of a cation and an anion increase, [what kind of intermolecular force increases?]
As the charge separation of a cation and an anion increase, Ionic Bond strength increases Note, the lattice energy getting more negative means that the lattice is more stable, meaning it is comprised of stronger ionic bonds.
Explain how fission and fusion both release energy
At first sight, it doesnΓÇÖt make sense that both fission and fusion release energy. The key is in how tightly the nucleons (protons and neutrons) are held together in a nucleus. If a nuclear reaction produces nuclei that are more tightly bound (i.e., at a lower energy) than the originals, then the excess energy will be released. It turns out that the most tightly bound atomic nuclei are around the size of iron (56 nucleons). Thus, if you split a nucleus that is much larger than iron (say, uranium with 238 nucleons) into smaller fragments, you will release energy because the smaller fragments are at a lower energy than the original nucleus. If instead you fuse very light nuclei (say, helium with four nucleons) to get bigger products, energy is again released because the nucleons in the products are more tightly bound than in the original nuclei. SUMMARY Nuclei lighter than iron release energy by fusion. Nuclei heavier than iron release energy by fission.
What is the periodic trend for atomic radius?
Atomic radius increases as you go left and down.
When balancing reactions, what two things do we consider
Atoms AND charge
Van Der Waals Equation of State
Attempts to correct for IMF and volume of gases Dont memorize*** a is a term that corrects for attractive forces (larger for gases that are larger and more polarizable) b is a term that corrects for volume (larger molecules have larger b) a is generally much larger than b
What is autoionization?
Autoionization is the phenomenon of water reacting with itself to make hydronium and hydroxide.
root-mean-square speed (urms)
Average molecular speed of molecules in a gas urms= [(3RT)/M]1/2 R is ideal gas (8.314) , T is temp, M is molar mass IN KILOGRAMS
The Nernst equation states: E=E°−(0.0592/n)log([X]anode/[Y]cathode) For a concentration cell that has a potential of 0.089 V and utilizes Ni2+ solutions at the anode and the cathode, which of the following statements correctly describes the molar cell concentrations [Ni2+]anode and [Ni2+]cathode and the direction of electron flow within the cell? A.[Ni2+] is greater at the anode; electrons flow from cathode to anode B.[Ni2+] is greater at the cathode; electrons flow from anode to cathode C.[Ni2+] is greater at the anode; electrons flow from anode to cathode D.[Ni2+] is greater at the cathode; electrons flow from cathode to anode
B A concentration cell employs the same electrode material and ionic solution for both the cathode and the anode, but the ion solutions surrounding the anode and cathode differ in concentration. As a result, the same half-reaction occurs at both electrodes, but it occurs as an oxidation at one and as a reduction (in the reverse direction) at the other. Accordingly, adding the two half-reactions yields a result of E┬░ = 0.00 V. The electrons will migrate from the cell with fewer cations to the cell with more cations until the cation concentration in each cell is equal. Because oxidation occurs at the anode, this is the source of electrons for the cell, which are transferred to the cathode where reduction occurs. Because the measured potential for the cell is positive (E = 0.089 V), the ion concentrations must have a ratio of [X]anode/[Y]cathode that is less than one so that the logarithmic term of the Nernst equation will be negative. A negative logarithmic value multiplied by the negative constant in the equation results in a positive value for E. Therefore, [Ni2+] is greater at the cathode, and the electrons in this cell will flow from the anode to the cathode.
What can BH3 reduce
BH3 reacts most readily with carboxylic acid carbonyl groups and therefore will selectively reduce carboxylic acids.
What determines sigma bond length
Because a σ bond involves end-to-end overlap of two orbitals, the length of a σ bond can be estimated as the sum of the atomic radii of the bonded atoms. Bonding between atoms with larger atomic radii positions the atomic nuclei farther apart and results in a longer σ bond (and vice versa). On the periodic table, atomic radii tend to decrease across a row (due to an increasing effective nuclear charge) and increase down a column (due to having an additional electron shell).
Why do we care about the difference between laminar and turbulent flow?
Because laminar flow can be approximated to be a conservative system with no dissipation of energy to heat, sound, etc.
Describe the unique characteristics of alpha hydrogens?
Because of how loosely the alpha hydrogen is held, it is relatively easy to break the bond between it and the alpha carbon, generating a carbanion.
Describe the energy in phosphate groups?
Because of the close association of so much negative charge, phosphates are high energy groups and are often coupled with reactants to make them more reactive. The more phosphates (PP or even PPP) the higher energy the group.
How does entropy always change during solvation?
Because solvation spreads molecules out, the change in entropy for this process is always positive.
Why do we need to know how to convert first order and second order graphs into line graphs?
Because we can get the slope of a line, and the slope of the line graph equals the rate constant k!
What does it mean for something to be ionized
Become an ion by gaining or losing an electron
What is beers law
Beers law is used to determine the concentration of a solution using a spectrophotometer. Basically it states that absorption of light by a solution is directly proportional to the concentration of a solution. It is written in the form: A= ELC where A is absorption, E (epsilon) is the extinction coefficient which is predetermined per solution, L is the length of light traveled in units of cm and C is the concentration
What is Beta minus decay?
Beta decay is when an unstable nucleus emits a beta minus particle AKA an electron. This happens when neutrons in the nucleus break down into a proton and an electron and an antineutrino. The proton stays in the nucleus, increasing the atomic number but conserving the atomic mass. The electron is emitted as the beta particle. An antineutrino is emitted as well
What is Beta plus decay?
Beta plus decay is when an atom emits a beta plus particle aka positron. This happens when an unstable proton turns into a neutron and a positron and a neutrino. The neutron stays in the nucleus and the positron is emitted as a beta plus particle. A neutrino is emitted as well. This causes the atomic number of the atom to decrease and the mass number to stay the same.
What is the fingerprint region in IR spectroscopy
Between 1500 and 400 cm-1 Dont even look at this, only experts can analyze it
Real vs. virtual, inverted vs. upright, magnified vs. reduced for objects placed beyond F, at F, or between F and mirror for converging mirrors. Also for diverging mirrors
Beyond F: real, inverted, magnified At F (or any focal distance away): no image (goes to infinity) Between F and mirror: virtual, upright, magnified Diverging always produces virtual, upright, and reduced image regardless of object positiion
Calculating new sound level when intensity of sound is changed by some factor
Bf=Bi + 10(log(If/Ii)) where If/Ii is the ratio of final intensity to initial intensity Sound level can also be referred to as relative intensity
What is boiling point elevation?
Boiling point elevation is the fact that, as you add nonvolatile solutes to a solution, it's boiling point increases. This is described mathematically below. Where Delta T is the change (elevation, so if our answer is 15, the boiling point goes UP by 15) in boiling point, Kb is a constant, m is the molality of the solution, and i is equal to the number of different particles the solute dissolves into. For example, NaCl would dissolve into two ions, so i would equal 2. glucose would have an i of 1
Antibonding vs bonding orbitals
Bonding orbitals place most of the electron density between the nuclei of the bonded atoms. Antibonding orbitals place most of the electron density outside the nuclei. Explanation: Electrons in bonding orbitals stabilize the molecule because they are between the nuclei. They also have lower energies because they are closer to the nuclei. Antibonding orbitals place less electron density between the nuclei. The nuclear repulsions are greater, so the energy of the molecule increases. Antibonding orbitals are at higher energy levels than bonding orbitals.
Breaking bonds is generally [endothermic or exothermic?]
Breaking bonds is generally endothermic
Describe the -OH IR peak
Broad peak in the 3300cm-1 region
What is bulk modulus?
Bulk modulus is a measure of an object's resistance to compression. Bulk modulus is lowest in gases (easily compressed) and highest in liquids and solids (almost impossible to compress)
First steps to a circuit problem
Calculate total circuit current, equivalent resistence, and total voltage (almost always given as voltage of battery). Usually you need to find resistence to get the current
Calorie vs calorie
Calorie is nutritional calorie, amount of heat needed to raise 1kg of water 1 degree celsius. 1000 cal in a Cal, so a 1 cal is the amount of heat required to raise 1g of water 1 degree celsius. 1Cal=4184J, 1cal=4.184 J
Unique characteristic of transition metals
Can have many different stable oxidation states (ex. Mn +2, 3, 4, 6, or 7)
geometrical isomers can or cant be seperated with Gas chromatography
Can, they will yield two different peaks
What is capacitance?
Capacitance is defined as the ratio of the amount of charge built up on either plate of the capacitor to the magnitude of the voltage across the capacitor.
Carbon dioxide and water form
Carbonic acid H2CO3, can lose two protons increasing acidity of solution
How are alcohols used as protecting groups?
Carbonyls are susceptible to reduction, and so in reduction reactions where you don't want to lose the carbonyl, you need to protect it somehow. This is accomplished by reacting aldehydes and ketones with 2 eq of alcohol or 1 eq of a diol to form acetals or ketals. Acetals and ketals are not easily reduced. So, you convert the carbonyl into an acetal or ketal, reduce the molecule the way you want to, and the convert the acetal or ketal back into a carbonyl by treating it with aqueous acid.
Describe the characteristic physical properties of carboxylic acids.
Carboxylic acids have both a hydrogen bond donor (-OH) and a hydrogen bond acceptor (C=O). This means they can engage in many hydrogen bonds, which results in high intermolecular forces and high boiling and melting points. Often exist as dimers in solution due to high IMF The other important characteristic of carboxylic acids is their acidity! The -O- is resonance stabilized after deprotonation, which makes the conjugate base stabilized. Note, most carboxylic acids will still only be weak acids. They still don't compare to the strong acids like HCl annd H2SO4
How do catalysts speed up reactions?
Catalysts are molecules that in some way shape or form stabilize the transition state of the reaction and lower its energy ** KAPLAN 162. This in turn lowers the activation energy of the reaction, which is used in the Arrhenius equation to determine the rate constant of the reaction.
Regardless of type of electrolytic cell, the cathode will always attract ______ and the anode will always attract ______ (from the salt bridge)
Cations, anions
What conformations does cyclohexane take to make ring strain as low as possible?
Chair, boat, and twist.
What does multiplying a vector by a negative number do?
Change the magnitude and direction of the vector.
What is the only way to change Kw (or any eq constant for that matter)
Changing temp (increasing temp increases Kw). It is just like any other eq constant in that only temp will change it
What is chelation?
Chelation is when a central cation is bonded to the same ligand in multiple places. This generrally requires large organic ligands that can double back to form more bonds with the central atom.
Biggest contributer to chemical behavior
Chemical behavior is governed largely by the number of electrons in an atom's valence shell. Atoms with the same number of valence electrons (same column of the periodic table) have similar chemical properties. #of neutrons does not have an effect. isotopes have very similar chemical behavior "The chemical behavior of an atom is determined primarily by its electron configuration, not by the number of neutrons in the nucleus. As a result, isotopes of the same element have nearly identical chemical properties (such as bonding and reactivity) but differ in their physical properties (such as density and mass)."
What are chemical properties?
Chemical properties are characteristics of processes that are associated with the chemical (how it reacts), not physical (what it's like) properties. Generally speaking, chemical properties are determined by the functional groups present in the molecule. sodium and chlorine making salt is a chemical change Change in composition
What is chemoselectivity?
Chemoselectivity refers to the tendency of chemicals to react with certain functional groups preferrentially over others. For example, in a molecule with an alcohol and a carboxylic acid, a reducing agent is more likely to reduce the very oxidized carboxylic acid over the slightly oxidized alcohol. Also, the nucleophile will likely go after the more oxidized carbon as that would lead to the highest partial positive electrophile. Aldehydes more reactive than ketones due to less steric hindrance Chemoselectivity is always related to the mechanism of the reaction. If you understand the mechanism, you'll be able to tell which functional groups will participate and which won't.
What is chirality?
Chirality is a word for handedness. What handedness means is that two objects are mirror images of one another, but due to the nature of their structure it is impossible to super-impose one on to the other. This is most easily seen in our hands. Hands are mirror images, but we can't super impose them.
How does one break a vector into components?
Choose two axes (vertical & horizontal or parallel & perpendicular) and use two vectors to represent the original vector.
What property does chromatography separate samples based on?
Chromatography uses mobile and stationary phases with different polarities and properties to separate molecules with different properties. The more affinity for the mobile phase, the farther the molecule will travel (elute). The more affinity for the stationary phase, the less the molecule will travel. We can use this to separate molecules from one another.
What is circular polarization
Circulation is a rarely seen natural phenomenon that stems from the interaction of light with certain pigments or specialized filters. Has uniform amplitude but a continuously changing direction, which causes a helical orientation of the propagating wave. The helix has average electrical field and magnetic field vectors that are perpindicular to eachother, like any other wave, with maxima that lie on the outer border of the helix
What are cis-trans isomers?
Cis-trans (formerly referred to as geometric isomers) are a specific subtype of diastereomer in which two identical substituents (hydrogens are not considered substituents) differ in their position around an immovable bond. Immovable bonds are double bonds and ring bonds. Cis isomers have the single substituent of interest on the same side of the bond, while trans isomers have the single substituent of interest on opposite sides of the bond. In molecules with more than one substituent on both sides of the bond (which really just means there are substituents instead of hydrogens) E and Z nomenclature is used instead. Note: E and Z is still a cis-trans isomer which is a diasteromer
Closed boundaries always correspond to [...]
Closed boundaries always correspond to nodes
What are colligative properties?
Colligative properties are physical properties of solutions that are dependent on the concentration of dissolved particles but not on the chemical identity of the dissolved particles
Compared to the reactants and products, the transition state will always have [less, more, or equal energy?]
Compared to the reactants and products, the transition state will always have more
How are standard reduction potentials calculated
Comparison with the standard hydrogen electrode (SHE) at standard conditions (298K, 1M, 1atm)
Concave lenses are [converging or diverging?] lenses.
Concave lenses are diverging lenses.
Concave mirrors are [converging or diverging?] mirrors
Concave mirrors are converging mirrors
What are the units of rate?
Concentration over time, usually Molarity over seconds.
What is conduction?
Conduction is the direct transfer of energy from molecule to molecule through physical collisions. Has to be directly touching, cant be anything in between the two objects
What are conjugated bonds?
Conjugated bonds are bonds that have free unhybridized p-orbitals adjacent to one another. This is basically only possible when there are sp2 hybridized carbons adjacent to one another. Electrons can sort of hop across adjacent p orbitals. Conjugation is the foundation of resonance.
What is constructive interference?
Constructive interference occurs when negative displacement waves interact with negative displacement waves, or when positive displacement waves interact with positive displacement waves. When these types of waves interact, the superposition wave will have a displacement equal to the sum of the individual wave displacements.
What is convection?
Convection is the transfer of heat by the physical motion of a fluid. (plume of smoke over fire is heat rising through air) (Remember, gases and liquids both behave as fluids!) warm water flowing over an object is convection NOT conduction. Object sitting in still water is conduction.
What is meant by converging and diverging in the context of optics?
Converging and diverging are whenthe optical device (mirror or lens) makes the real light rays come closer together or further apart, respectively, after they reflect/refract.
Convex lenses are [converging or diverging?] lenses.
Convex lenses are converging lenses.
Convex mirrors are [converging or diverging mirrors?]
Convex mirrors are diverging mirrors
What are the units of charge?
Coulombs C
How does one determine the harmonic of a standing wave in a closed pipe?
Count the number of quarter wavelengths.
What is reaction coupling?
Coupling is when you pair two reactions so that their overall delta G is negative and the overall reaction is spontaneous. Ex. exergonic combustion of glucose with endergonic formation of peptide bonds
Covalent bonds are generally formed between [...]
Covalent bonds are generally formed between nonmetals and nonmetals
What are the characteristics of covalent compounds?
Covalent compounds contain discrete molecular units with relatively weak intermolecular interactions, and therefore lower boiling points and melting points. They do not break down into constituent ions, and are therefore poor conductors of electricity.
How is sound created and how does it traverse a medium
Created by a mechanical vibration. Causes a disturbance of particles along the waves direction of propagation. The particles themselves do not move with the wave, but the oscillate in equilibrium, which causes small regions of compression to alternate with small regions of rarefaction (decompression). These alternating regions of increases/decreased particle density travel through the material.
Should you place an ammeter in series or parallel?
Current is equivalent across elements in series and split across elements in parallel. Therefore, you should place the ammeter in series so that you're measuring the actual current. If you place an ammeter in parallel, it will split the current and the value you measure will be lower than the actual current.
What is current? Direction of flow in terms of potential?
Current is the amount of positive charge passing through a conductor per unit of time. Flows from high potential to low potential (remember positive goes from high to low and negative (electrons) goes from low to high, both trying to reduce potential energy)
What is a cyanohydrin?
Cyanohydrins are molecules with a -CN and -OH group on the same carbon.
Sebacic acid (HOOC−(CH2)8−COOH) is a naturally occurring dicarboxylic acid that is also found as a normal urinary acid. Which procedure should be followed to determine the amount of sebacic acid present in 200 mg of an unknown sample composed primarily of sebacic acid and a small percentage of neutral impurities? A.Dissolve the sample in 0.1 M acid, then titrate the solution with 0.1 M base and an indicator. B.Dissolve the sample in 0.1 M acid, then titrate the solution with 0.1 M acid and an indicator. C.Dissolve the sample in 0.1 M base, then titrate the solution with 0.1 M base and an indicator. D.Dissolve the sample in 0.1 M base, then titrate the solution with 0.1 M acid and an indicator.
D In a titration, a measured amount of a solution with a known concentration (titrant) is added to another solution containing an unknown concentration of the compound to be measured (analyte). In acid-base titrations, an acid is titrated with a base (or vice versa). The resulting acid-base neutralization reaction produces a change in pH, which is monitored by a pH indicator that signals the equivalence point of the neutralization. The analyte must be fully dissolved before it can be measured. Sebacic acid has low solubility in water due to a high nonpolar hydrocarbon character. A base will convert the carboxylic acid groups into highly polar ionic salts with much higher aqueous solubility. Once dissolved, the carboxylate ions can then be titrated with an acid. Subtracting the number of moles of base (such as KOH) in the initial solution from the number of moles of acid (such as HCl) required to reach the equivalence point during the titration will give the number of moles of carboxylate groups from sebacic acid in the sample.
What is Dalton's Law of Partial Pressures?
Dalton's law of partial pressures states that the total pressure in a container with a mixture of gases will be equal to the sum of the independent pressures.
What is decarboxylation?
Decarboxylation describes the complete loss of the carboxyl group as carbon dioxide. This occurs more readily under heated conditions and with 1,3-dicarboxylic acids or beta keto acids (ketone with carboxylic acid). Proceeds through 6 membered cyclic intermediate Note: Having only one carbon in between makes it muchh easier. It can still be done with more bit much harder. Also two ketones or a ketone and an aldehyde CANNOT do this
What is damping/ attentuation
Decrease in amplitude of a wave caused by an applied or nonconservative force. If applying a periodic force equal to the resonant frequency, one would think amplitude would grow infinitely. Due to constraints with friction/ structure there will be a max amplitude. Shattering of a wine glass due to persistent loud singing (at a frequency equal to the wine glass natural frequency)will cause the glass to shatter because the amplitude grows too large.
Exponential decay equations
Delta(n)/delta(t)= -lambda (n) lambda is the decay constant, n is the number of radioactive nuclei that have not yet decayed n=n0e-(lambda)(t) n0 is the number of undecayed nuclei at time 0, n tells us how many nuclei will remain after t seconds (n0 can also be in moles or concentration) lambda= (ln2)/T1/2=.693/T1/2 T1/2 is half life
How does ring strain affect lactams?
Depending on the number of substituents in a ring (5 and 6 are the only real stable ones) the ring strain imparted on a molecule can severely weaken its stability. Even the amide bond, a very strong bond normally, can be easily cleaved if it is shoved into an awkward ring. This means they are more reactive to hydrolysis or anything that involves breaking the ring
What is destructive interference?
Desctructive interference occurs when the a positive displacement wave interacts with a negative displacement wave. The superposition wave will be equal to the sum of the individual wave displacements, but because the waves have opposite signs, the superposition wave will be smaller than either of the individual waves.
What is the electrodeposition equation
Determines the number of mole of element being deposited on a plate as well as the amount of gas liberated during electrolysis mol M= It/nF mol M is amount of metal ion being deposited at specific electrode, I is current, t is time, n is the number of electron equivalents for a specific metal ion, F is faraday constant.
What three things is proton NMR good for
Determining the relative number of protons and their relative chemical environments Showing how many adjacent protons their are by splitting patterns Inferring certain functional groups
What does it mean to be diamagnetic?
Diamagnetic materials are made of atoms with no unpaired electrons and that have no net magnetic field.
How do diamagnetic materials behave when exposed to magnets?
Diamagnetic materials are weakly repelled by magnets (slightly antimagnetic)
What are diatomic molecules?
Diatomic molecules are seven elements that do not exist alone in nature. Instead, they bond with themselves to form more stable di-atomic (2 atom) compounds. They are H2, N2, O2, F2, Cl2, Br2, I2. MNEMONIC: The six in the seven and Hydrogen. Six of the diatomic elements are in a seven shape on the right side of the periodic table, and the only other one is Hydrogen.
dichloromethane vs water solvation
Dichloro is an Organic solvent, dissolves less polar things than water. Water works really well with charged things because they are so polar. If it is in acid form it often needs to be treated with base to gain a charge so water can dissolve it.
How do dielectric materials work?
Dielectric materials are inserted in between the plates of a capacitor in order to increase the capacitance. Because dielectrics are insulators, inserting them in between the plates of a capacitor decreases the strength of the electric field between them. Capacitance is inversely related to the field between the plates, so lowering the strength of the field increases the capacitance. Reduces energy stored in capacitor
What is diffraction?
Diffraction is the spreading out of waves as they pass through a narrow opening or around an obstacle.
What is diffusion?
Diffusion is the spontaneous movement of molecules from high concentration to low concentration.
What is dilution?
Dilution is when you lower the concentration of something by adding more solvent.
What is dispersion?
Dispersion is when various wavelengths of light separate from one another. Commonly seen in prisms Explanation: When light travels through a medium, different wavelengths travel at different speeds. SInce index of refraction is related to speed (n=c/v), different wavelengths have different indexes of refraction. So when white light enters a prism, each wavelength will be refracted by a different amount. Red is always least (so it is on top) and violet is always most refraction (on bottom). THis makes sense because violet has the shortest wavelength. Larger wavelengths have smaller refractive indices while smaller wavelengths have larger refractive indices as predicted by the above equation Note: wavelength and speed changes but frequency does not when light enters a medium with a different index of refraction Violet light is refracted more than red light because violet light has a higher frequency/lower wavelength. Violet light is slowed down to a greater extent so it will bend more as it exits a glass prism. The order of bending from least bending to most bending based off color and wavelength is ROYGBIV "Instead, the index of refraction is greater for shorter wavelengths (proportionate to frequency), so the index of refraction of most glasses is normally higher at shorter wavelengths, while the refractive index of air is more uniform. This is what causes light at the violet/blue end of the spectrum to bend more, entering and leaving the prism than red light, and each successively longer wavelength bends less, causing the fanout of colors." Note: violet will refract least through diffraction grating Deflection angle due to a diffraction grating depends on the spacing between the grating lines, and not on the index of the grating (assuming air-grating-air). Longer wavelengths are deflected through larger angles by a diffraction grating
What is displacement?
Displacement is a vector quantity that describes an objects change in position in space. It is an arrow from initial position to final position.
Are dissociation reacitons typically endo or exothermic
Dissociation reactions are typically endothermic processes because energy must be added to the system (as heat) to dissociate (break) the bonds in the reactants. Thus products will have more energy than reactants on a delta H graph
What is distance?
Distance is a scalar quantity that describes the length that an object has traveled. It is a tallying of the total length an object has moved to get from its initial position to its final position.
What is distillation?
Distillation is a process by which a mixture of two liquids is separated by boiling one of the liquids out.
How can we increase the effectiveness of separatory funnel separations?
Do them over and over! More small extractions is better than 1 big one. At best, you'll pull 99% of the solute you want into one of the layers, but there is always some amount left, and sometimes it can be a lot. So, you can take the filtrate form a sep funnel extraction and run that through another sep funnel extraction to make it even purer.
When multiplying vectors, what type of product should be used to create a scalar?
Dot product
What kind of molecular orbitals go into double bonds?
Double bonds are made of 1 sigma bond with 1 pi bond around it.
Is going down or across a better predictor of atomic radii
Down. Chlorine is bigger than nitrogen
What is a dynamic equilibrium?
Dynamic equilibrium is when reactants are converted into products, but at the same rate at which products are converted into reactants, resulting in no net change in the substance and allowing it to remain at equilibrium.
How does E/Z nomenclature work?
E/Z is supposed to be used on molecules that have an immovable bond with more than one substituent on both sides, but it is basically just interchangeable with cis- trans- isomerism. First one must assign priorities to the groups on both sides of the bond. If the high priority groups are on the same side of the bond, it is given Z configuration (Zame side). If the high priority groups are on opposite sides of the bond, it is given E confiugration (Epposite side).
How to calculate magnitude of electric field along the perpendicular bisector of the dipole
E=k*(p/r3) Field Vectors will point opposite of p (as defined by physicists, pointing from neg to pos) So field vectors along bisector will point from pos to neg
When EM aka light waves enter denser medium how does their speed change? When sound waves enter a denser medium how does their speed change?
EM slows down sound speeds up
What is the EMF or Ecell?
EMF or Ecell is the difference between standard reduction potentials between two half cells. If you need to balance by multiplying half reactions by a common factor, dont multiply Ered or Eox, they dont depend on moles present
Eletric potential vs electric potential energy
Electric potential (V) is the property of points in space. Electric potential can be defined in several ways: The value of the electric potential at a point in space numerically gives the amount of work that needs to be done to bring a unit positive charge from infinity to that point. A charge q is said to have a potential energy of Vq if it is at a point in space which has a potential of V. For example, if you place a charge q at a point, space nearby will have a non-zero value of potential. The electric potential at a point due to a charge at a distance r from it is given by: V=kq/r What is Electric Potential Energy? Electric potential energy (U) is the property of a system. Two charges in the vicinity of each other are said to have potential energy. The electric potential energy associated with two charges separated by a distance r is given by: U=kq1q2/r
Electric potential of 3 charges around a point
Electric potential is a scalar not a vector! They donΓÇÖt cancel out so just add them Electric field would cancel out
Electrolytic cells have a [positive or negative?] Delta G
Electrolytic cells have a positive Delta G
What is Electron Domain Geometry and how do we predict it with VSEPR?
Electron Domain Geometry is the shape made between the electrons on the central atom and the central atom, regardless of whether or not the electrons are in a bond or not. In this case, we simply count up the number of electron pairs, bonded or nonbonded, and refer to VSEPR theory for the shape.
What is Electron Affinity?
Electron affinity is the amount of energy released when an an atom gains an electron. In other words, Electron Affinity describes how easily an atom can capture an extra electron.
What is electron capture?
Electron capture is when an unstable nucleus combines an inner electron with a proton to form a neutron while releasing a neutrino. The neutron stays in the nucleus. This lowers the atomic number while keeping the mass number the same.
What factors affect the acidity of carboxylic acids
Electron donating groups decreases acidity (-NH2 and -OCH3) Electron withdrawing groups increases acidity (-NO2) Note: in dicaboxylic acids the other COOH is electron withdrawing and thus increases acidity, but once one proton is removed, the other group acidity decreases
What kinds of groups increase the strength of a base?
Electron donating groups near the basic hydrogen. This is because these electron donating groups help to cancel the positive charge of the conjugate acid, stabilizing it. Remember, the more stable the conjugate acid, the stronger the base.
What kinds of groups increase the strength of an acid?
Electron withdrawing groups near the acidic hydrogen. This is because these electron withdrawing groups spread the charge density of the conjugate base out, stabilizing it. Remember, the more stable the conjugate base, the stronger the acid.
What is Electronegativity?
Electronegativity is a measure of how much force with which an atom can pull electrons towards itself. The more electronegativity an atom has, the stronger it pulls electrons towards itself.
What does it mean for elements to be in parallel?
Elements in parallel are elements which are placed side by side on different paths. Because there are multiple paths, the current will split and be distributed amongst the elements.
What does it mean for elements to be in series?
Elements in series are elements which are placed sequentially on the same path. Because there is still only 1 path, the each element will have the full current pass through them.
What is the eluent?
Eluent is another name for the mobile phase in chromatographic methods.
Are enantiomers or diastereomers mirror images?
Enantiomers are nonsuperimposable mirror images. Diastereomers are not mirror images
What do you call a reaction with a positive Gibbs Free Energy?
Endergonic
Endergonic reactions are [spontaneous or non-spontaneous?]
Endergonic reactions are non-spontaneous
What is the first law of thermodynamics?
Energy is never created nor destroyed, only transferred from one form to another. In other words, the total energy at the beginning of a problem must equal the total energy at the end of a problem.
What is potential energy?
Energy of an object by virtue of its position in a system or some other intrinsic quality.
What is an energy shell?
Energy shells are different distances at which electrons can orbit a nucleus with stability. The more energy an electron has, the further out they go.
What is the difference between heat and enthalpy?
Enthalpy is just heat under constant pressure, a commonly made assumption.
What is entropy?
Entropy is the measure of the spontaneous dispersal of energy at specific temperatures. As entropy goes up, more energy gets dispersed or the same ount of energy gets dispersed farther.
What is Eo?
Eo is the standard potential. It is the potential change associated with the reaction being described at standard state conditions
What are esters?
Esters are compounds with a carbonyl bonded through an oxygen to another carbon.
Carbooxylic acids can be converted to ____ in one step and ____ in two steps
Esters, amides, alcohols in one step alkenes in two steps (reduction and then elimination) Note: this is a shit question by kaplan as their are multiple "steps" in each process
What is the difference between evaporization and boiling?
Evaporization is the natural conversion of some liquid molecules into gas that occurs as a result of the equilibrium between the phases. Boiling is the rapid bubbling of the entire liquid with the rapid release of the liquid as gas particles. This happens when the liquid exceeds its boiling temperature.
What do you call a reaction with a negative Gibbs Free Energy?
Exergonic
Exergonic reactions are [spontaneous or non-spontaneous?]
Exergonic reactions are spontaneous
When is solvation endothermic vs exothermic and at what temperatures is each favored. Example of each situation
Exothermic when new solute-solvent interactions are stronger than original solute-solute and solvent-solvent interactions, favored at lower temps (gases into liquids) Endothermic when new interactions are weaker than original ones, favored at high temps (most things)
Force on a particle in an electric field
F=qE
What does it mean to be ferromagnetic?
Ferromagnetic materials, like paramagnetic materials, are made of atoms unpaired electrons and randomly oriented magnetic fields that cancel out. The only difference is that ferromagnetic fields become strongly magnetized by magnets as opposed to becomming weakly magnetized by magnets.
Describe the Michael Addition
First, a carbanion is generated by deprotonating the alpha hydrogen of a ketone or aldehyde. Next, the carbanion is used as a nucleophile to attack an alpha beta unsaturated carbonyl compound, which is a molecule with a double or triple bond between the alpha and beta carbons of a carbonyl. The double bond in the alpha beta unsaturated carbonyl is pushed to the carbonyl carbon, which pushes carbonyl double bond up to the oxygen. The electrons in the double bond are siphoned by a base, which allows the carbonyl double bond to reform.
Describe the first step of aldol condensation
First, an enolate is formed by treating a carbonyl with a base and then acid. The Enolate reforms a carbonyl and a carbanion, which it uses to attack another carbonyl (almost always itself as there shouldn't be multiple carbonyl compounds in the same flask.) At this point, a carbon-carbon bond has been formed. The electrons that got pushed to the oxygen pick up a proton, forming an aldol.(alcohol and aldehyde) Note: this is still called aldol condenstation when we are working with ketones
Calculating emperical and molecular formula given grams of atoms within molecule
First, divide gram of each element by molar mass of element. Next, divide all those answers by the lowest answer. Third, that ratio is emperical formula. If the total molar mass of that is different from the total grams they gave, you need to multiply it to get molecular formula. Ex. we have 112g molecule and emperical formula is 56g/mol, multiply each atom by 2 to get molecular
Describe the first step of the Strecker Synthesis.
First, the carbonyl carbon of the aldehyde is activated by the ammonium's acidic proton. Second, the deprotonated ammonium (ammonia) attacks the activated carbonyl. Third, the hydroxyl group takes the extra proton from the amino group and turns into water, a decent leaving group. Fourth, a double bond forms between the amino group which displaces the water leaving group. Fifth, Cyanide as a nucleophile attacks the double bonded electrophilic carbon to generate an aminonitrile.
Describe the esterification reaction
First, the carbonyl is protonated to increase the electrophilicity of the carbonyl carbon. Then an alcohol uses its free electrons to attack the carbonyl. The original -OH group gets protonated, turning it into water, a decent leaving group. The carbonyl reforms and the water leaving group leaves. Finally, the carbonyl oxygen deprotonates, resulting in an ester.
Describe the synthesis of an amide from a carboxylic acid?
First, the free electrons on the nitrogen attack the electrophylic carbonyl carbon. This pushes the double bond electrons up to the oxygen. Then the alcohol group gets protonated to make it a decent leaving group. Finally, the carbonyl reforms and the water group leaves. Leaving an amide. General mechanism below. Specific example (can be carried out in acidic and basic solution to drivve it forward)
What are flagpole interactions?
Flagpole interactions refer to a specific type of steric strain that is exhibited by axial molecules on a ring. This is why it is more stable to place large groups in equatorial positions. You avoid this strain.
What does it mean to be a fluid?
Fluids are things (gases and liquids) that can flow and conform to the shapes of their containers.
What is fluorescence?
Fluorescence is when a species absorbs high frequency light, but doesn't emit it all right away. Instead, it emits multiple photons with increasingly less energy in a series of steps where the total energy of the emitted photons is equal to the energy of the absorbed photon. Because the light is being emitted in multiple steps, it takes a lot longer. So, when you shine high frequency light on fluorescent material, it will absorb the light and glow for a while afterwards (Slow emission of many photons) as opposed to just flashing a quick color like it would if it emitted one photon in one step.
What are the steps of the half reaction method?
For basic, add OH- to both sides at the end of the problem. Merge H+ and OH- to form water and then cancel out water. For this example we would add 16OH- to each side.
Images and mirrors/lenses
For diverging systems(both lenses and mirrors): at any distance: virtual and upright (reduced) For converging systems (both lenses and mirrors): when object is between focal length and lens/mirror: virtual and upright (magnified) When object is at focal length: no image When object is between f and 2f: real and inverted (magnified as well) When object is at 2f: real and inverted (same size) When object is greater than 2f: real and inverted (reduced size)
MP and BP periodic trend
For example a Group 1, 2, 13 and 14 the boiling point decreases down the group due to increased electron shielding between the atoms, leading to a weaker attraction between the nucleus and electrons. For group 15, 16, 17 and 0 the boiling point increases due to strong Van Der waal forces.
Calculate molar solubility equation of Ca3(PO4)2 in water
For molar solubility this would be (3x)3(2x)2=108x5 where x is molar solubility of Ca3(PO4)2
What is the critical modification one must make to the right hand rule for negative charges?
For negative charges, flip the direction of the vector that resulted from the right hand rule. If the right hand rule tells you the force on a proton is coming out of a page, that means that for an electron, that force will be going into the page.
What is formal charge?
Formal charge refers to the difference between the number of valence electrons on an atom in a molecule and the number of valence electrons on an atom in its neutral unbonded state. Generally speaking, the larger the formal charge (in either the negative or positive direction), the less likely that the molecule will arrange itself in that lewis structure.
What is Kf and how can it be used to make predictions about concentration of complex ion
Formation or stability constant of the complex ion in solution kf= [products]x/[reactants]x for Ag++2NH3=[Ag(NH3)2]+ Ag+ gets formed from dissociation from AgCl (described by Ksp= [Ag][Cl]) Models the formation of the complex ion after the ion has been donated, Kf is significantly larger than Ksp so the formation of Ag+ is the rate limiting step Even if Ksp is low, all of the AgCl added will be turned into ions because the complex ion keeps pulling out Ag which means more Ag will be formed So if we add a mol of AgCl, We dont use ksp to determine how much ag is produced, we assume its a mol This will then equate to the amount of complex ion produced because its 1:1 ratio Overall, the addition of a complex ion increases solublity of an otherwise insoluble substance
What is Fractional Distillation?
Fractional Distillation is like simple distillation, except that there is a fractionation column connected to the distillation flask. The purpose of the fractionation column is to give the vapor more surface area on which it can condense (0ften contains glass beads or steel wool). This is useful for liquids with close boiling points. For example, a liquid with a 90C and a liquid with a 100C boiling point will both boil at 90C. It's just that the 90C liquid will boil completely while the 100C liquid will boil a little bit. However, if there is a long fractionation column, the tiny bit of 100C liquid that boils will never make it to the condenser, so you're safe from contaminating your distillate!
What is freezing point depression?
Freezing point depression is the fact that, as you add nonvolatile solutes to a solution, it's freezing point decreases. This is described mathematically below. Where Delta T is the change (depression, so if our answer is 15, the freezing point goes DOWN by 15) in freezing point, Kf is a constant, m is the molality of the solution, and i is equal to the number of different particles the solute dissolves into. For example, MnCl2 would dissolve into three ions, so i would equal 3.
Equation for shear force of a liquid
Fshear=(eta)[(delta V)/(delta y)] eta is dynamic viscosity delta V is change in velocity between two locations delta y is distance between both locations
Describe a rechargeable cell/ battery
Functions as both a galvanic and electrolytic cell
What is it called when a solid goes to a liquid?
Fusion or Melting
What are Gibbs free energy and entropy at equilibrium
G is at minimum and S is very high (energy spread evenly)
Galvanic cells have a [positive or negative?] Delta G
Galvanic cells have a negative Delta G
Which form of radiation is most dangerous if it is outside the body?
Gamma rays are the most dangerous outside the body because they can penetrate the skin/clothes easily and cause damage within the body.
What is gauge pressure?
Gauge pressure is the difference between the absolute(hydrostatic) pressure in/on something and the atmospheric pressure that the object always feels. Essentially, the gauge pressure is how much "extra" pressure is on something. Pgauge=P-Patm=(P0+Rho(g)(z))-Patm =Rhofluid(g)(z) when P0=Patm
What is Gay-Lussac's Law?
Gay-Lussac's Law states that pressure is proportional to temperature.
What are geminal diols?
Geminal diols are diols with two hydroxyl groups on the same carbon.
What factors affect the speed of Sn2 reactions?
Generally, the less substituted the carbon being attack, the less steric hindrance and the more room for nucleophiles to attack. Sn2 reactions are second order, so increasing the concentration of the substrate or the nucleophile will increase the speed of the reaction as well.
What factors affect the speed of Sn1 Reactions?
Generally, the more substituted the carbocation, the more stable it is because alkyl groups donate electron density and help deal with the positive charge. By stabilizing the rate determining step, the reaction goes faster. Sn1 Reactions are first order reactions, therefore increasing the concentration of the substrate (not the nucleophile though) will also increase the speed of the reaction.
How does stability of leaving group affect electrophile strength
Good leaving groups will create carbocations so they make the electrophiles much stronger Ex. CH3Cl is a better electrophile than CH3OH
What is Graham's Law of effusion and diffusion?
Graham's law allows us to compare diffusion and effusion rates (which equal speed) between gases by relating the square root of their molar masses. Where the r's are the diffusion or effusion rates of the two gases, and the MM's are the molar masses. A gas with 4 times the molar mass will travel half as fast as lighter gas
Where are the Alkaline Earth Metals on the periodic table?
Group 2.
What is High Performance Liquid Chromatography?
HPLC is a specific type of column chromatography in which high pressures and sophisticated computer systems are used to apply complex solvent gradients and temps to separate compounds that have even tiny differences in their affinities for the mobile and stationary phase. This is method is preferred for separating compounds that are more similar than they are different, or with smaller sample sizes. It can also be used if capillary action is expected to affect results Similar apparatus to gas chromatography but uses pressurized liquid rather than gas (therefore liquid eluent/mobile phase) polar stationary phase
Venturi flow application to bernoullis
Height as compared to a datum remains constant at both points, so rho(g)(h) portion of eq is constant on bpth sides. flow rate is higher at point two, which means dynamic pressure is higher(1/2 rho v2), which means absolute pressure needs to be lower at point 2! thus column of fluid is lower
What is Hess's law?
Hess's law is just a consequence of the fact that enthalpy is a state function. It states that enthalpies of a series of step by step reactions will just add up, and the overall enthalpy of the series of step by step reactions will be equal to the sum of each individual step. Can split up reactions into steps Ex. C(s)+2H2(g)->CH4(g) = 1. C(s)->C(g) Delta H1 2. 2 (H2->2H) two times Delta H2 3. C(g)+4H->CH4(g) Delta H3 Add them all together to get overall delta H. Remember formation of bonds relases energy so delta H3 is negative https://socratic.org/questions/what-is-the-standard-enthalpy-of-formation-of-methane-given-that-the-average-c-h
Describe heterogenous catalysts
Heterogeneous catalysts are usually solids interacting with reactants that are either liquids or gases. The reactants adsorb onto the solid catalyst surface, which will either promote the interaction of two reactants or will weaken the bonds in the reactants. Both aspects serve to increase the reaction rate by stabilizing the high-energy transition state.
If we are running TLC with 4 different levels of polar molecules with ether as the eluent, what will happen to movement if which switch the eluent to hexane
Hexane will be able to displace the molecules less, leading them to be stuck to the silica easier, reducing movement and thus Rf values. This is why TLC uses a slightly polar eluent, we want the molecules to move somewhat
Reverse phase vs normal phase HPLC
High-performance liquid chromatography (HPLC) is a purification technique used for small sample sizes. The instrumentation consists of a sample injector, a column (stationary phase), solvent under pressure (mobile phase), a detector, and a computer for data acquisition. Two types of columnsΓÇönormal-phase (NP) or reverse-phase (RP)ΓÇöcan be used, depending on the polarity of the compounds being separated. NP-HPLC is used to separate relatively nonpolar compounds and consists of a polar stationary phase (typically silica) and a nonpolar mobile phase. RP-HPLC is used to separate polar compounds and has a nonpolar stationary phase (typically C-18 alkyl hydrocarbon) and a polar mobile phase. Nonpolar compounds in a mixture will interact more with the stationary phase than polar compounds, causing nonpolar compounds to have a longer retention time.
Frequency relation to energy (higher frequency means _______ energy)
Higher frequency means higher energy
How do we perform extractions?
How do we separate a polar and a nonpolar compound in solution? First, find two immiscible solvents with different polarities. The polar layer is called the aqueous phase and the nonpolar layer is called the organic phase. Mix these in a separatory funnel. Next, place your mixed solution into the separatory funnel with the two solvents. Third, shake it all up, making sure to vent the separatory funnel to let any gas out. Fourth, let it settle out. Remember, the two solvents you picked earlier are immiscible, so over time they will naturally separate, like oil and water. The polar compound in the solution will have dissolved mostly into the aqueous layer and the nonpolar compound in the solution will have dissolved mostly into the organic layer. Carefully separate the layers, and viola, you have separated your two products! A rotary evaporator (rotovap) can be used to evaporate the solvent Unwanted impurities can be removed by running a small amount of solute over the compound of interest(called a wash)
What is Hund's Rule?
Hund's rule states that energy of the various orbitals in a sublevel are equal. What this implies is that each orbital in the sublevel will receive one electron before it receives two electrons.
What are Hydrogen Bonds?
Hydrogen bonds are just a particularly strong dipole-dipole interaction formed when hydrogen binds certain very electronegative elements (F,O,N). Hydrogen bonds are so strong, that they can act as intermolecular forces (attraction between different molecules) or intramolecular forces (attraction between a hydrogen dipole within the molecule and another element within that same molecule). MNEMONIC: Hydrogen bonds pick up the FON (phone): Hydrogen bonds are only seen in molecules containing a hydrogen bound to Fluorine, Oygen, and Nitrogen.
What are hydroxyquinones?
Hydroxyquinones are quinones with one or more hydroxyl groups. Note: a hydroquinone sounds very similar bit is actually a benzene ring with two hydroxyl groups slightly less electrophillic than quinones
How does one calculate the power of a resistor?
I is current through the resistor, V is voltage drop across the resistor (not across circuit), R is the resistence Can substitute in V=IR to derive different forms Since P=E/delta t, E=P(delta t), so any of those power equations multiplied by time will give power dissipated over the course of time
What must be true of the molecule and the stretch it undergoes for it exhibit IR absorption?
IR absorption can only happen in dipole molecules with asymmetric stretches. So, that means O2, or Br2 would never show on an IR spectra because they are diatomic and there is no net dipole. Acetylene also doesn't give anything due to symmetry.
Fundamentally, how is IR spectroscopy useful?
IR spectroscopy is useful for figuring out the types of bonds (-NH, C=O, -OH, etc.) in a sample.
In what direction will the reaction proceed if Q < Keq? What is ΔG?
If Q < Keq then the ratio of products to reactants is lower then it would be at equilibrium. Therefore, we'd expect the reaction to go in the forward direction to reach the equilibrium ratio. ΔG is negative
Deviations from Raoult's law
If solute-solute and solvent-solvent interactions are better than solute-solvent interactions (we're talking about two very different molecules, like ethanol and hexane), then the molecules won't want to stay in solution and will readily evaporate, increasing vapor pressure higher than what the law predicts If solute-solute and solvent-solvent interactions are Worse than solute-solvent interactions (we're talking about two very compatable molecules, like nitric acid and water), then the molecules will want to stay in solution and will not readily evaporate, decreasing vapor pressure to lower than what the law predicts
Increasing distance between plates of parallel plate capacitor effect on charge/ voltage
If the capacitor is connected across a battery, the voltage will stay constant at the battery voltage. Charge will decrease If the capacitor is charged and disconnected, the voltage will rise. Assume the capacitor holds charge Q, then Q = CV, or V = Q/C Separating the plates reduces C, so if Q remains constant V must increase proportionally.
When can we ignore the autoionization of water?
If the concentration of acid or base is significantly greater than 10-7M. If it is equal or less you need to take in water autoionization. Ex. calculate pH of a 1E-8 solution of HCl. You might think it is 8 but that doesnt make sense because there is more acid than when at neutral so it has to be slightly below 7. Kw=[H3O+][OH-]=[x+10-8][x]=10-14 with x being concentration of hydronium and hydroxide from autoionization. Solving for x is outside scope of MCAT but know that actual H+ concentration will be x+10-8 which is slightly below pH7. Kaplan 356
When a light ray refracts from one medium to another, how does its speed change?
If the second medium's index of refraction is lower, the light ray goes faster. If the index of refraction is higher, the light ray goes slower.
Describe Gas Chromatography
In Gas Chromatography, also known as Vapor Phase Chromatography (VPC) is similar to all the other chromatographic methods. The only big difference is that the eluent (mobile phase) is a gas (usually helium or nitrogen) instead of a liquid. The stationary phase is composed of crushed metals or polymers in a 30 foot coiled tube. The column is in a temperature regulated oven to keep the sample in the gas phase as it travels through the column.
In a circuit, current flows from [...]
In a circuit, current flows from the posititive terminal to the negative terminal Aka higher potential to lower potential electrons flow from negative to positive
In a galvanic (voltaic) cell, the cathode is [positive or negative?]
In a galvanic (voltaic) cell, the cathode is positive This makes sense because the cathode is where the electrons are going to do reduction. If the cathode is positive, electrons want to go there. This means the cell will release energy from the favorable reaction, like a galvanic cell.
What are london dispersion (Van Der Waals) forces?
In a nonpolar covalent bond, we expect the electrons to be equally shared between the atom's electronegativities are the same. But, even though the electrons aren't actively being pulled to one atom, they can still randomly assort themselves in the orbital in such a way that one atom has a little tiny bit more electron density than the other one. This results in a spontaneous, very short lived, very small dipole. The negative end of this temporary dipole will attract to the positive end of some other molecule's temporary dipole. This low-level but ever present attraction between the spontaneous dipoles of non-polar compounds is referred to as London Dispersion Forces, and is the weakest of the intermolecular forces.
In a parallel configuration, each element will feel the same [...]
In a parallel configuration, each element will feel the same voltage Note: the current will split on each path. The path with lowest resistence will get the most current. They are inversly proportional
What is the dipole moment?
In a polar compound, the dipole moment is the net vector of electrical charge in the molecule. In diatomic molecules, this will simply be the vector from the partially positive element to the partially negative element. However, in molecules with multiple polar bonds, the multiple electrostatic vectors will have to be summed in order to get the net vector.
How do we determine the limiting reactant?
In a reaction with two reactants, you can convert the moles of one reactant into the moles of another reactant using normal stoichiometric methods. So what you do is... 1. Identify the moles of both reactants. 2. Pick one of the reactants, it does not matter which. 3. Use the balanced equation to convert the moles of the reactant you picked into the moles of the other one. 4. Now compare the converted moles of the reactant to the original mole of the other reactant. The smaller number is the limiitng reactant.
In a solution where IP < Ksp, there will be [precipitate or no precipitate?]
In a solution where IP < Ksp, there will be no precipitate
In a solution where IP = Ksp, there will be [precipitate or no precipitate?]
In a solution where IP = Ksp, there will be no precipitate
In a solution where IP > Ksp, there will be [precipitate or no precipitate?]
In a solution where IP > Ksp, there will be precipitate
How are redox titrations similar to acid-base titrations?
In acid base titrations, the pH and thus the transfer of protons is what is used to reach the equivalence point of the reaction. In a redox reaction, the E cell of the reaction and thus the transfer of electrons is what is used to reach the equivalence point of the reaction.
In an electrolytic cell, the cathode is [positive or negative?]
In an electrolytic cell, the cathode is negative This makes sense because the cathode is where the electrons are going to do reduction. If the cathode is already negative, electrons don't want to go there. This means you have to put energy in to make it happen, like an electrolytic cell.
How do reactions respond to changes in temperature as described by Le chatelier's principle?
In an endothermic reaction, heat is a reactant, so increasing the temperature shifts the equilibrium right. On the other hand, in an exothermic reaction, heat is a product, so increasing the temperature shifts the equilibrium left.
What does it mean to be axial or equatorial?
In cyclic molecules, substituents can either be axial (perpendicular up or down) or equatorial (sticking out up or down). As you can see from the picture, both the axial and equatorial positions alternate their direction around the ring. Starting from the top left carbon, the axial bonds go Up, Down, Up, Down, Up, Down. Starting from the top left carbon, the equatorial bonds go Down, Up, Down, Up, Down Up.
What is perceived color
In general, the perceived color of a substance is complementary to the color of the wavelength that is maximally absorbed by that substance. When the basic colors of the visible spectrum (red, orange, yellow, green, blue, and violet, or ROYGBV) are arranged in a wheel with red and violet next to each other, a color's complement is the color directly across from it on the wheel. The question states that Compound 1 absorbs light with a 448 nm wavelength, which corresponds to violet light and to yellow as the complement. After Cu2+ is added, the absorption maximum changes to 623 nm and corresponds to orange light, the complement of which is blue. Therefore, upon the addition of Cu2+, Compound 1 must undergo a change in electronic structure that causes the solution to change from yellow to blue.
Describe intramolecular anhydride formation.
In molecules with aromatic rings and carboxylic acids, the carboxylic acids can attack one another to form anhydrides.
In nuclear fission, energy is [consumed or released?]
In nuclear fission, energy is released you may think it would take energy to split atoms, but The products are more stable than starting nuclei (because the starting nuclei are unstable radioactive elements), so it releases enrgy
In nuclear fusion, energy is [consumed or released?]
In nuclear fusion, energy is released Products are more stable than the starting nuclei
Other than being used as leaving groups, how are tosylates and mesylates useful?
In oxidation reactions, alcohols can be oxidized even if you don't want them to be. Converting to Tosylate or Mesylate protects the alcohol from oxidation, so you can convert, oxidize the molecule the way you actually want to, then convert the tosylate or mesylate back into an alcohol (with acid). Be careful though, tosylates and mesylates are good leaving groups so make sure you don't accidentally performe a substitution reaction and knock them off.
What does it mean for two waves to be in phase?
In phase waves have a phase difference of 0 degrees, and are therefore lined up exactly (in phase). Below is a picture of two red waves that are in phase. The blue wave shows the superposition wave sum (adding both aplitudes). Constructive interferencce
Resistors in series vs in parallel voltage drop relation to battery voltage
In series they should all add up to the battery voltage. In parallel they should all equal the battery voltage and all equal eachother
Describe the Gabriel Synthesis
In the Gabriel Synthesis, Phthalimide attacks DiethylBromomalonate to form a highly substituted cyclic intermediate (phthalimidomalonic ester) . This intermediate is treated with a base to form a relatively stable carbocation. The carbocation attacks an organic molecule with a good leaving group using SN2 substitution. The R group you pick here will determine which amino acid ends up getting made. The new intermediate is treated with base and water to release the dioic acid part of the intermediate and break the ring.Creates phthalic acid with two carboxy groups (esters converted to carboxylic acids) Treatment with acid and heat will decarboxylate the 1,3-dicarbonyl to form an amino acid.
What are the reactants and products of the Strecker Synthesis?
In the Strecker Syntehsis, one starts with an aldheyde (cant be ketone), NH4Cl, and KCN. This is a technique used to synthesize amino acids.
Describe a simple distillation?
In this method, a distilling flask is filled with a solution of mixed liquids. The distilling flask is connected to a distilling column, which is a condenser and a thermometer. The distillation column is connected to a receiving flask. The distilling flask is heated until one of the liquids boils out. As the one liquid boils, it rises up as vapor. At the top of the flask the vapor will condense. Some of the liquid will fall back down into the flask, but most of it will get trapped in the condenser which sends it to the receiving flask, where it is collected in pure form as distillate.
Describe the production of an Imine
In this reaction, an ammonia molecule serves as a nucleophile and attacks the carbonyl carbon. The oxygen picks up two hydrogens to become water. The attached amino group uses its free electrons to generate a double bond with the carbon, which kicks of the water leaving group. Finally, the double bonded amino group loses a proton to reduce its formal charge and increase the stability of the molecule, resulting in an imine. Considered a condensation reaction Imines will tautormerize to form enamines
What are the three exceptions to the Octet Rule?
Incomplete Octet Elements: These elements are stable with less than eight electrons in their valence shell. Hydrogen (2), Helium (2), Lithium (2), Beryllium (4), and Boron (6). Expanded Octet: Any element in period 3 and greater can hold more than eight electrons. For example, Phosphorus (10), Sulfur (12), Chlorine, (14) and others. Odd numbers of Electrons: Any molecule with an odd number of valence electrons cannot distribute those electrons to give 8 to each atom, so one of the atoms won't have a full octet in these molecules.
Dielectrics in circuit capacitors
Increase in capacitance results from increase in stored charge (because when in a circuit the voltage will stay constant)
What is induction in the context of acids and bases?
Induction is when an electronegative group somewhere on the acid spreads the negative charge of the conjugate base out. This stablizes the acid and the effect increases when the group is more electron withdrawing and when it's closer to the proton that will be lost (the atom that the negative will be on) so FCH2COOH is doper than CH3COOH. Having electronegative groups close to the atom that will accept the proton on a base is actually worse. THe base wants electron donating groups (aka groups that are less electronegative, so NH3 is weaker than CH3NH3 because the methyl donates to the nitrogen making it more electron dense and more likely to take a proton)
Describe titration of weak acid and weak base
Initial pH between 3 and 11 (depending on whether titrand is acid or base). Very shallow drop at equivalence point. Equivalence point will be near neutral pH
What is inorganic phosphate?
Inorganic phosphate is just a term used to describe phosphate molecules in biological systems. It is denoted with Pi. Also called phosphoric acid
Instantaneous velocity and instantaneous speed are [...] [Explanation]
Instantaneous velocity and instantaneous speed are equivalent This makes sense because it takes time to change the direction of a vector. In velocity, you're moving at some speed and you can change direction at some point. In speed, you're just moving at some speed not worrying about direction. In any given instant, you are only travelling in one direction. It takes time to turn and go into different directions, messing with displacement and therefore velocity. Therefore, with a timescale of 0 (instantaneous) velocity is only going in one direction and is therefore equivalent to instantaneous speed.
What is integration in the context of NMR?
Integration is when you take the area under the curve, which is kind of like saying how big it is. The integration values are arbitrary, but they will relate to one another in the same ratios that the protons relate to one another. For example, in the NMR below, there are 3 b hydrogens and only 1 a hydrogen. If you were to take the integral of both the b and th a curve, you would find the ratio to be 3:1.
How is the amplitude of a sound wave related to its intensity?
Intensity increases proportional to the square of the amplitude. This means that, if you double the amplitude, you will quadruple the intensity.
How is intensity of sound related to your distance from it?
Intensity of sound is inversely proportional to the square of the distance. This means that if you are twice as far away from a sound, it will be 1/4 times as intense. If you are 3 times as far away from a sound, it will be 1/9 times as intense. Note: this is because surface area of a sphere is 4(pi)r2 so as it travels further the surface area increases exponentially thus distributing power more thinly, reducing intensity
What is intensity of sound (and equation/units)?
Intensity of sound is the average rate of energy transfer per area a sound wave makes on a surface. Where P is power and A is the area the sound power passes through. 4pi(r)2 is surface area of sphere Units: W/m2
What is thin film interferance
Interference of rays reflecting on either surface of the film (REFLECTION not refraction) leads to rainbow (think oil or bubbles)
What are intermolecular forces?
Intermolecular forces are weak electrostatic forces that molecules will exhibit between one another. These Intermolecular forces are very important in determing physical properties of the molecule, such as melting points, boiling points, and density.
What are intramolecular forces?
Intramolecular forces are strong electrostatic interactions between the atoms within a molecule, i.e. the actual bonds in the molecule.
Does the magnetic force do any work on a moving charge?
Intuitively, it may seem like the answer is yes, but if you do the math you'll see it is no! Because the lorentz force is a cross product, by definition it must be perpendicular to the velocity of the charge. When a force is perpendicular to an objects displacement, no work is done (W = Fdcos(theta))
Resistence in parallel relation to current
Inversly proportional. If we have two branches, and the right branch has double the resistence, it will draw half the current. Remember the junction rule which means current before the split must equal both branches added up
Ionic bonds are generally formed between [...]
Ionic bonds are generally formed between metals and nonmetals
What contributes to the high MP and BP of Amino acids
Ionic interactions, heavy, lots of H-bonding
What special case must we remember when considering Ionization energy?
Ionization energy increases massively once the atom has an octet. This is because a full octet is very stable and it takes a lot of energy to knock an electron out of an octet. Example of this phenomenon shown below.
What is Ionization Energy?
Ionization energy is the energy required to remove an electron from a sample of gaseuos atom. The greater an electron's effective nuclear charge, the stronger the nucleus holds the electron, and therefore the higher its ionization energy.
Doubling distance affect on electric field of an isolated vs connected capacitor
Isolated means no change, connected means it halves
What does a first order reaction suggest about the start of the reaction?
It begins when the molecule undergoes a chemical change all by itself, without a chemical interaction, and usually withoit physical interaction with any other molecule
What are the units of rate constant?
It depends. Each reaction can have different rate constant units, and the MCAT can even ask you about this specifically. You can always figure out the units of a rate constant given the reactants. This is because you know that the rate will have units of Ms-1 and any reactant will have units of M. Just use dimensional analysis to determine the units of rate constant.
What does first, second, or third order kinetics actually mean in terms of molecules reacting
Its the # of molecules involved in the reaction First order means one just changes on its own Second order means two collide (can be A with B, A with A, or B with B) Third order means three collide (many combos, ex. is 2 A and 1 B)
Entropy units
J/K
How does one calculate the equivalent resistance for resistors in series?
Just add them up
What is a dielectric material?
Just another way of saying insulator.
For a forward reduction reaction with a known reduction potential, how do we find the oxidation potential of the reverse reaction?
Just flip the reaction to make it an oxidation and flip the sign on the standard potential.
How are esters named as substituents and parent chains?
Just like with carboxylic acids, esters won't ever really be a substituent, they'll usually be the parent chain. But, in those rare cases where this isn't true, esters substituents are given the name alkoxycarbonyl- There are two terms to an ester parent name. The second term is the parent chain with the ester, and it is named by dropping the -oic acid and replacing it with -oate. The first term is the name of the group to which the ester is bonded.
What kind of molecular orbitals contribute to a single bond?
Just sigma bonds.
What is the naming convention for 5 and higher carbon molecules?
Just use the normal greek roots for numbers. 5. Pent 6. Hex 7. Hept 8. Oct 9. Non 10. Dec 11. Undec 12. Dodec Etc.
Kinetic energy relation to temp and speed for gases
KE=(1/2)mv2=(3/2)KbT (for one particle, for one mol multiply by avogadros) Kb= Boltzmann constant= 1.38E-23 J/K
What is the reaction of a weak monoprotic acid with water and what is the Ka expression?
Ka=[H3O+][A-]/[HA]
What is Boltzmann's constant
Kb= Boltzmann constant= 1.38E-23 J/K
What is keto-enol tautomerization?
Keto-enol tautomerization is the tendency for ketones/aldehydes to enter into equilibrium with their enol isomers (Keto and enol forms are NOT resonance structures). The enol tautomer is less common than the OG form when in equilibrium. This is because the keto tautomer is more thermodynamically stable (more eletron density closer to electronegative oxygen)
What is the general rule for common naming ketones?
Ketones are commonly named by listing the alkyl groups in alphabetical order, follwed by -ketone.
If using a constant or any value with joules, molar mass must be
Kg/mol because joules are derived from kg!!!
What is kinetic friction?
Kinetic friction is the force that acts between two objects sliding against each other.
During a phase change, is kinetic or potential energy changing
Kinetic is constant (evidenced by the fact that temp isnt increasing) potential increases (liquid water is more free to move than solid)
Of the two, which is made faster, kinetic product or thermodynamic product and why?
Kinetic product is made faster, lower activation energy.
Calculating max kinetic energy from ejected electrons (photoelectric effect)
Kmax=hf-W W is the work function of the metal in question Notice: this calculates MAX kinectic energy. The actual kinectic energy can banywhere between 0 and Kmax, depending on specific subatomic interactions between the photon and the metal ion.
What are some strong bases used to deprotonate alpha carbons
LDA, hydrides
What is laminar flow?
Laminar flow is smooth and orderly flow. It is usually represented as parallel layers of fluid flowing smoothly over one another. lines on outside are flowing slower than near object
What are leaving groups?
Leaving groups are the groups that are displaced during heterolytic reactionns. Generally speaking, weak bases are stable with extra electrons, and so they make good leaving groups. (I-, Br-, and Cl-). Good leaving groups make for stronger electrophiles Leaving groups can also be strengthened by inductive effects from electron withdrawing groups and resonance. Alkanes and hydrogens are almost never leabing groups (think: CH3- and H- would be reactive af)
Light travels [faster or slower?] in materials with low indices of refraction.
Light travels faster in materials with low indices of refraction.
Light waves are [longitidunal or transverse?] waves
Light waves are transverse waves
How does water behave when it reacts with an acid?
Like a base.
In what way can the metallic bond be described?
Like a sea of electrons floating over a rigid lattice of metal cations. This flowing nature of the electrons over metals is what makes metals such good conductors of electricity. More accurately it is an equal distribution of the charge density of free electrons across all of the neutral atoms within the metallic mass
How do we name amides as substituents and parent chains?
Like all the other carboxylic acid derivatives, amides won't usually be substituents, but when they are, they are called carbamoyl- or amido- Amides are named by dropping the -oic acid of the parent name and adding -amide. The groups bonded to the amide nitrogen are designated N-
How do we approach acid base problems?
Like normal equilibriums. The same principles we used to find the concentration of species in equilibria from before will apply well to acids and bases.
Single slit/lense interference equation
Location of the dark fringes (minima) is given by: asin(theta)=nlambda a is the width of the slit theta is the angle between the line drawn from the center of the lens to the dark fringe and the axis of the lens n is an integer indicating the number of the fringe theta is the wavelength of the incident wave Bright fringes are always halfway between dark fringes The central bright fringe is twice as wide as the bright fringes on the side. As the slit becomes narrower the central maximum becomes wider
Longer or shorter hydrocarbons have higher standard heat of combustion
Longer
How do we visually determine the harmonic of a string attached at both ends?
Look at the number of Antinodes/ number of half wavelenghts
How do you determine the number of valence electrons an atom has?
Look at the periodic table and determine which column the atom is in. (the numbers above the periodic table are the number of valence electrons. The noble gases can be thought of as having 0 valence electrons or 8 valence electrons.)
How can one determine how much of a floating object lies beneath the surface of the water in which it is floating?
Look at the specific gravity. The specific gravity will be equal to the percentage of the object that is submerged. For example, an object with a specific gravity of .92 will float with 92% of its volume submerged in the water. Objects with a specific gravity of more than 1 sink in water and are therefore completely submerged.
What does a concave mirror look like?
MNEMONIC: Like entering a Cave
How to approach common ion problem
Make an ice table and use your initial concentration of ion in the initial product section and then add whatever x you need to add
What do we do if we are working with a lewis structure and seem unable to get a stable octet on all the atoms?
Make sure that one of the elements you are working with isn't an exception to the octet rule. For example, remember some elements can handle less than 8 electrons, and every element in period 3 or larger will be able to hold extra electrons in their d orbitals.
Making bonds is generally [endothermic or exothermic?]
Making bonds is generally exothermic
What is a mass spectrometer?
Mass spectrometry involves firing molecules of varying weights through a circular tube and a magnetic field. The higher the molecule's weight, the less it is deflected by the magnetic field. The lower the molecule's weight, the more it is deflected by the magnetic field. We can use the differences in their deflection to separate molecules and identify them individually.
What is a paramagnetic material
Materials with atoms with unpaired electrons will orient their spins in direction of magnetic field and thus weakly attracted to the magnetic field (Can be magnetized)
How does mechanical advantage work?
Mechanical advantage is when we use a machine of some sort to reduce the amount of force needed to achieve some outcome. This reduction in force is accomplished through an increase in distance through which the force has to be applied, thus conserving energy. (Work is the same both with and without pulley)
As intermolecular forces in a molecule become stronger, how do melting and boiling points change?
Melting and boiling are both examples of separating atoms from one another. Atoms are held together by intermolecular forces. Therefore, as intermolecular forces get higher, boiling and melting points get higher. This is because you need more temperature energy to overcome the intermolecular forces and break the atoms up into liquid or gas form.
Metals [gain or lose electrons] so as to achieve a stable octet
Metals lose so as to achieve a stable octet
Molar mass vs molecular weight cs equivalent weight vs atomic mass vs atomic weight vs mass number
Molar mass- mass of one mole of a compound molecular weight- mass of one molecule (usually in amu but can be converted to grams) equivalent weight- mass of a compound that gives one mol of particle of interest atomic mass- actual Mass of one atom (takes into account binding enrgy and electrons) atomic weight- weighted average of all isotopes mass number- number of protons and neutrons
What is spectroscopy?
Molecules of different types have different energy states which are associated with certain types of rotation, vibration, electron absorption, and nuclear spin transitions. Depending on the molecule, it will have different energy states. A molecule can be promoted to a higher energy state by shining light of the correct energy (frequency) on it. The molecule will spontaneously revert back to a lower energy state, releasing that same light. We can shine light of different kinds on chemicals and see what kind of light we get back to determine the identity of the molecule. This is the fundamental principle behind spectroscopy.
What kinds of molecules make good oxidizing agents?
Molecules that get reduced well (i.e. attract electrons). (usually have electronegative atoms especially oxygen) (think: non metals usually gain eletcrons)
When a molecule has resonance structures, which of its resonance structures will it behave like?
Molecules with resonance structures will behave as though they were resonance hybrids, that is to say, the hybrid structure of all the resonance forms combined. Some resonance structures are more stable than others (this can be determined with formal charges), and therefore will dominate the overall resonance structures. In these cases, the molecule will act mostly like the dominant resonance structure, but will still have small characteristics of the other resonance structures.
Moving a charge from one equipotential line to a different one [...]
Moving a charge from one equipotential line to a different one requires work
Equations for magnification, focal length, and power for multiple lens systems
Multiple lens systems in contact behave as a single lens with equivalent focal length given by 1/f= 1/f1+1/f2+1/f3... Power given by: P=P1+P2+P3... For lenses not in contact, the image of one lens becomes the object of another lens. The image of the last lens is considered the image of the system. (Ex. microscopes and telescopes) Magnigication is given by: m=m1*m2*m3
What must be true for Raoult's law to hold
Must be an ideal solution, meaning the attraction between the molecules of the different components in the mixture is equal to the attraction of any one component in its pure state solute-solute attraction=solvent-solvent attraction=solute-solvent attraction so molecules have to be SIMILAR for the law to hold
What are myopia and hyperopia and what lens is used to correct them
Myopia- Uses divergent lens to correct for nearsightedness (Near objects are clear, but cant see far) Hyperopia- Uses convergent lens to correct for farsightedness (Far objects are clear, but cant see near)
Fundamentally, how is NMR spectroscopy useful?
NMR spectroscopy is the most useful of the spectroscopic methods because we can use it determine the entire structure of a molecule.
Do capacitors store charge?
NO! Everyone will tell you yes, but they are wrong. Capacitors store energy in the form of an electric field, not charge. It is true that charge will accumulate on the plates of capacitors, but this is an equilibrium with the rest of the circuit and for every charge that enters one side of the capacitor, a charge will leave the other side of the capacitor.
Does changing voltage/charge of a capacitor affect capacitance
NOOO Dont look at C=Q/V and assume changing one will change capacitance. Changing one will change the other so that capacitance remains constant Capacitance is dependent on the geometry of the capacitor (C=e0(A/d))
Do rate orders have anything to do with rate of consumption of reactants?
NOOOOOOOOOOOOOOOOOOOOOO RATE ORDERS DON'T RELATE TO STOICHIOMETRIC COEEFICIENTS UNLESS ITS THE SLOWEST STEP OR A SINGLE STEP REACTION
What is the Arrhenius Equation?
NOTE: It is more important you understand the relationship between these variables. It is unlikely you will have to calculate using the Arrhenius Equation. The Arrhenius Equation is a rigorous equation that gives the rate constant for a reaction given various variables. Where k is the rate constant of the reaction, A is the frequency factor, e is the natural base, Ea is the activation energy of the reaction, R is the ideal gas constant, and T is the temperature.
When do we assign positive or negative values to work?
Neg. when work is being done on the system (compression) pos. when work is being done by the system (expansion). applies to Q-W version so if system compresses it becomes Q+W because neg times neg equals pos
Cis or trans?
Neither!! If there are two of the same group that canΓÇÖt be ranked one over the other then it isnΓÇÖt qualifying for cis trans or EZ
What is the archetypal form of a Neutralization reaction?
Neutralization reactions are a specific type of double-displacement reaction in which an acid reacts with a base to produce a salt.
Does electroyltic flow require a salt bridge
No
Benzaldehyde structure and limitation in aldol reactions
No alpha hydrogen!!! therefore it cannot be a nucleophile
Are double displacement reactions considered redox reactions
No because the oxidation states usually don't change. They also only have a net ionic equation if the phases of any elements change. If both sides are all aqueous there is no net ionic equation
What does it mean to be in thermal equilibrium?
No net heat is flowing between objects in thermal contact.
Regarding photoelectric effect, what is the relationship of the kinetic energies of the emitted electrons to light intensity
No relation. intensity relates to photocurrent
If a reaction is irreversible, is there a reverse rate
No you ********
Do products ever appear in or affect the rate law?
No! Rate is dependent on the concentration of the reactants, so only they are included.
When placing substituents names before the parent name with prefixes, do we consider those prefixes for alphebatization?
No! di-, tri-, etc. are not used in alphebatization. This means that Ethyl- would come before di-methyl, because E comes before M and we ignore the D of the prefix. This rule applies to the hyphenated prefixes like n- and tert- as well. This rule does NOT apply to the non-hyphenate prefixes like iso, neo, and cyclo.
Do strecker and gabriel synthesis generate an optically active solution?
No! they generate racemic mixtures which are not optically active
Does Hess's law only apply to enthalpy?
No, Hess's law applies to any state function.
Does the path taken from one equipotential line to another matter?
No, any path from equipotential line to another will take the same amount of work.
Are all resonance structures created equally?
No, certain resonance structures will be much more stable and dominate for that reason. If one resonance structure is way more stable than the other, the molecule might be 99.9999% like the more stable resonance structure with a little tiny bit of the other resonance strucure contributing. Things that make a resonance structure more stable include: Some resonance structures will have less formal charge on the atoms, which is more stable. Some resonance structures will have more full octets or full octets on highly electronegative atoms, which is more stable. A resonance that creates aromaticity is very stable
Does earth create a bigger gravitational force on you than you do on it?
No, earth and the person create equal forces on eachother, but earths mass makes it have an apparent acceleration of zero
If percieved frequency is doubled, is it necesarrily true that 1. The detector is moving toward the source at a velocity equal to the speed of sound 2. The source is moving toward the detector at a velocity equal to half the speed of sound
No, either or could be true. Saying one specifically has to be true is false because either or could be true.
Do two objects need to be in physical contact to be in thermal contact.
No, it is possible for objects to be in thermal contact without touching one another, although, objects in thermal contact are usually in physical contact too.
Is pH=7 always neutral?
No, only at 25 degrees celsius (298K) . Once temp changes, Kw changes
You approach someone who holds a speaker , is the doppler effect the same as if they had approached you (while holding the speaker) at the same velocity
No, plug in the numbers to see this
Even though there is a defined difference between cis and trans and E/Z isomers, does it really matter?
No. A lot of people will just use the Cahn-Ingold-Prelog priority rules to determine E/Z with a multisubstituent molecule, but then still end up calling the molecules cis or trans. The point of this flashcard is to remind you to be flexible in the way you apply the definitions. If you see a molecule called cis-, even if it isn't technically a cis trans isomer, you still know what they are trying to say: higher priority substituent on the same side of the molecule.
Do you split up solids when writing net ionic equations
No. AgCl stays as AgCl and does not split into Ag and Cl alone.
Do all compounds with internal electronegativity differences have dipole moments?
No. Although most compounds with internal electronegativity differences will have internal dipoles, if the structure is symmetric, the internal dipoles will all cancel out resulting in a nonpolar compound with no dipole moment.
Do we see geminal diols often?
No. Geminal diols spontaneously dehydrate to produce carbonyl compounds.
Is the equilibrium constant a constant?
No. The equilibrium constant is different for every reaction and is different at evey temperature.
Do the stoichiometric coefficients of a balanced reaction tell you the orders of the rate law?
No. The stoichometric coefficients rarely have anything to do with the order of rate law. There are only two very rare cases when the stoichiometric coefficients tell you the order of the rate law. 1. If the reaction mechanism is a single step and the balanced overall reaction is reflective of the entire chemical process 2. When the complete reaction mechanism is given, the orders of the reactants will be equal to the stoichiometric coefficients of the slowest step, assuming there is no intermediate in the slowest step. 3. When a complete mechanism is given, each step is a single step so the stoich applies when writing rate for each individual step (before combining algebraically to get overall order)
Do catalysts just speed up the forward reaction?
No. They lower the transition state energy, which makes it easier to go forward through the reaction or backward through the reaction.
Describe an electrolytic cell
Non spontaneous (needs external battery power) Half reactions dont need to be seperated Electrodes can be basically any material as long as it can resist high temperatures and corrosion.
How much work is done in uniform circular motion
None, force vector is perpidicular to displacement
Nonmetals [gain or lose electrons] so as to achieve a stable octet.
Nonmetals gain so as to achieve a stable octet.
If a solution has a saturated catalyst, can increasing concetration of reactants affect rate?
Nope, it can only affect first, second, or higher order reactions. Ones that RELY on catalyst will not be affected if catalyst is full (think michaelis mentin graph)
What is Normality?
Normality is equal to the number of equivalents of interest per liter of solution. An equivalent of interest is a measure of the number of molecules there are to react. To calculate the normality of a solution, you must know what purpose the solution serves and which species is the reactive species. Then, the normality will equal the molarity of the reactive species multiplied by the number of times it could react. For example, H2PO4 could dissociate twice to give 2 protons into solution. This means, in a solution of base, it will be able to react with the OH groups not once but twice. Therefore, it's normality will be equal to twice it's molarity. (6M would be 12N)
Does common ion effect affect Ksp
Not a chance
Does a molecule with polar bonds always exhibit polarity?
Not always. Remember, symmetrical molecules can cancel out the polarity in their bonds.
How long does an atom stay in an excited state?
Not long at all. Atoms want to be in ground state because it is the most stable configuration. Even when forced into an excited state, atoms will revert back to ground state.
Is the rate constant a constant?
Not really. It needs to be experimentally determined for every reaction. But, if you are given the rate constant for a reaction and it matches the conditions of your reaction, you can use it like a constant in the rate equations.
Can bomb calorimeters determine bond energy
Not unless you have a metric shit ton of info
Can ketones do aldol condensations *
Not usually, although they can do other aldol reactions like subsititutions
Does change in gibbs free energy have anything to do with rate
Nothing at all. It is all in activation energy. An endergonic reaction will proceed faster than exergonic if it has a lower activation energy. This is because "proceed" just means proceed to equilibrium, not who makes the most product.
A dipole is at rest in a field. If you suddenly invert the field, what happens?
Nothing! the angle will go from 0 degrees to 180, but the sin of both is 0, meaning there is 0 torque. If the field moves in any direction but directly oppisite what it was there will be torque.
How does one calculate the weight of a given volume of a substance?
Notice that, if you multiply density by volume, you will get mass, at which point this equation simplifies to the hitherto described equation Fg=mg. Therefore, this equation is actually just a combination of the known force of gravity equation and the equation to calculate density.
What types of nuclei are NMR active?
Nuclei with odd mass numbers, odd atomic numbers (odd atomic but even mass number WILL work), or both will haave a magnetic moment when placed in a field. This means that 12C, for example, is not NMR active (no magnetic moment).
How do you name cis- and trans- on rings?
On a ring, substituents can either be on the same side or on opposite sides of the ring. These molecules are geometric isomers to one another, and must be able to be identified. If the substituents are on the same side of the ring, the molecule is given the suffix cis- If the substituents are on opposite sides of the ring, the molecule is given the suffix trans-
What are the three rays that can be drawn in order to use a ray diagram for mirrors?
One must draw at least 2 of the following in order to find the image. 1. A parallel ray that is reflected through the focal point. 2. A ray that passes through the focal point and is reflected parallel to the mirror. 3. A ray that passes straight through the mirror to the center of curvature and is reflected with an angle equal to its incident. Rays 1 and 2 used below All 3 rays used below.
What are the 2 special d-orbital modifications we must make to the electron filling order?
Only occurs in d and f (NOT P) The 2-special cases of electron filling exist for the Chromium group of elements (Chromium and all the elements below it on the periodic table) and the Copper group of elements. For these elements, instead of taking on a normal 4s23d4 configuration, they will take a 4s13d5 configuration. This is because filling the 3d orbital up with 5 electrons (half) provides the atom with extra stability. So much extra stability, that the atom will pull an electron from the s orbital to fill the d orbital. The same thing happens for the copper elements, only the d orbital electrons go from 9 to 10 instead of 4 to 5. For example, Copper's electron configuration is actually 4s13d10 instead of 4s23d9
What is optical activity and what are the two types?
Optical activity refers to the rotation of plane-polarized light by chiral molecules. Enantiomers will rotate plane polarized light the same magnitude, but in opposite directions. If you know the direction of rotation for one config, its enatiomer will be the exact oppisite. But between diastereomers it they could both rotate the same way or be opposite like enantiomers, theres no way to tell how the other diasteromer will rotate light from one given. A molecule that rotates plane polarized light to the right aka clockwise, is dextrorotary (d-) and is labeled (+). A molecule that rotates plane polarized light to the left aka counterclockwise is levorotary (l-) and is labeled (-). MUST BE DETERMINED EXPERIMENTALLY, DOESNT RELATE TO R and S/ D and L (sugars)
What is the Aufbau Principle?
Orbitals are filled in order of lowest energy to highest energy. The order of low energy orbitals to high energy orbitals can be determined using the diagonal method shown below. An electron not in its lowest energy orbital is called excited and will shortly return to its lowest energy orbital. energy of orbital can be determined by adding first two quantum numbers (n+l rule)
What is osmotic pressure?
Osmotic pressure is the pressure associated with concentration gradients. Think about it. When solutes go from high concentration to low concentration, what makes them move? It's osmotic pressure that makes them move!
What does it mean for two waves to be out of phase?
Out of phase waves have a phase difference that is not equal to 0 degrees.
Overall, [...] energy correlates with lower stability and viceversa
Overall, higher energy correlates with lower stability and viceversa
Overall, higher energy correlates with [...] stability and viceversa
Overall, higher energy correlates with lower stability and viceversa
Oxidation number vs. formal charge
Oxidation assumes the more electronegative atom takes all the electrons and formal charge assumes equal division where each atom takes 1 electron. The reality is in between. Ex. CO2 has 0 formal charge on any atom, but has oxidation numbers of +4 and -2. The answer is somewhere in between
Moving through the ETC, what happens to oxidation and reduction potentials
Oxidation potential gets lower (less likely to give up electrons as we move through) Reduction potential gets higher (more likely to take electrons as we move through)
What is an oxidation state?
Oxidation state is the charge an element will usually take if it is going to form an ion and become part of an ionic compound. For most elements, this will be the charge assocated with an octet configuration. For example, all of the Alkalie Metals (Na, K, Li) will always have an oxidation state of +1 in ionic compounds. The same is true for some Halogens and their -1 oxidation state. Then, there are some elements that are usually going to have the oxidation number associated with their octet configuration, but not always. Finally, there are the transition metals, many of which take on many different oxidation states. It is important to know the few stable transition metals and then just figure out what the oxidation state of any other transition metal is during the problem.
In organic chemistry, what is a quick way to determine whether or not a molecule was oxidized or reduced?
Oxidized molecules are molecules that have bonds to oxygen, carbons, nitrogens, or halides (heteroatoms). Reduced molecules are molecules that have bonds to hydrogen. If a molecule undergoes a reaction and afterwards it has more bonds to hydrogen than to heteroatoms, it was probably reduced.
What are some good oxidizing agents (in orgo)?
Oxidizing agents get reduced themselves, and therefore will have features that make them attractive to electrons. Two main examples would be electronegativity (O2, Cl2, etc.) and high positive charge on an atom (Mn7+ in MnO4- and Cr6+ in CrO42-. Peermanganate and chromate PCC (pyridinium chlorochromate) can oxidize primary alcohols to aldehydes and then stop
Presbyopia treatment and why
P = 1/f, where f is the focal length of the lens in meters), it is evident that an increase in focal length decreases the refractive (bending power of a lens). Now you should ask yourself, what does a lens with a large focal length even look like? Does a it have a big curve or is it flat? Remember that the focal length is determined by creating an imaginary circle using the boundary of the lens, finding the radius of that circle, and dividing it by two. Now its evident that big focal length = flat lens. Why is any of this important? People with presbyopia (i.e. old people) have lenses that have crystallized and now have trouble bending. This means that their lenses have a big focal length...low refractive power...can't bend light well...image will converge too late (i.e. behind retina). How do we treat them? With converging (convex) lenses!
Some example polar/ non polar solvents
POLAR: water, deuterium oxide (heavy water for NMR), ethanol, methanol, acetone, methyl ethyl ketone, isopropanol, n-propanol, acetonitrile, DMSO (dimethyl sulfoxide) or deuterated DMSO (heavy DMSO for NMR), DMF (dimethyl formamide) Somewhat nonpolar: chloroform, diethyl ether, deuterated chloroform NONPOLAR: pentane, hexane, benzene, toluene (pentane and hexane are the least polar of the series) Extra: "Diethyl ether is a solvent with very low polarity (non-polar). It is an excellent solvent for lipids, resins and mineral fats." In addition other solvents of this type are: chloroform, benzene, toluene, xylene, ketones, hexane, cyclohexane and carbon tetrachloride. A special case is fluorinated solvents, which are more non-polar than conventional organic solvents.
How do parallel plate capacitors work?
Parallel plate capacitors are composed of two plates, one connected to the positive terminal one connected to the negative terminal, separated by a small distance. The plate connected to the positive terminal will build up positive charge and the plate connected to the negative terminal will build up negative charge. The difference in charge between the two plates will cause an electric field to develop between them. The energy that is stored in a capacitor is stored in the electric field it creates.
How are mole fraction of a gas and partial pressure related?
Partial pressure of a gas will be equal to its mole fraction times the total pressure of the gas. Where PA is the partial pressure of A, XA is the mole fraction of A, and PT is the total pressure.
What is a partition coefficient?
Partitioning is the equilibrium of a molecule between the mobile and stationary phases in a chromatograph. Therefore, the partition coefficient is like the equilibrium constant for a molecule to be associated with the mobile phase and the stationary phase. The lower the partition coefficient, the faster the molecule elutes.
What are the rules of peak splitting?
Peak splitting follows the n+1 rule, where the number of adjacent hydrogens, n, + 1 equals the number of peaks after splitting.
What is percent composition?
Percent composition is the percent by mass of a specific compound that is made up of a given element. Only refers to one compound. Know that mass percent composition only pertains to one compound not all the products in a reaction. If products are AgCl and MgO, and you need to find percent composition of Ag in product, it is mass percent of Ag in AgCl not Ag out of everything
What is percent yield?
Percent yield is the ratio of the actual yield to the theoretical yield multiplied by 100%. In practical terms, a Percent Yield of 90% means that you obtained 90% of the absolute maximum value you could have gotten if you did everything perfectly.
What are the Oxidation Number Assignment Rules (what are peroxides as well)?
Peroxides are any molecule with two oxygens single bonded to eachother Noble gases have 0
In an isolated system, describe the phases of the molecules?
Phase changes are an equilibrium, so in an isolated system given enough time, solid, liquid, and gaseous forms of the compound will exist in an equilibrium of some sort. Note: this equilibrium can so prefer one phase, such as solid, that you cannot see the tiny amounts of liquid and gas present.
What are some of the unique properties of phosphoric acid?
Phosphoric acid has 3 acidic protons with pkA's of 2.15, 7.2, and 12.3. This means that phosphate is a super good buffer because it will buffer solutions of ph: 1.15-3.15 (plus or minus one first pKa) 6.2-8.2 (plus or minus one second pKa 11.3-13.3 (plus or minus one third pKa.)
What are physical properties?
Physical properties are characteristics of processes that are associated with the physical (what it's like), not-chemical (how it reacts), properties. These are things like melting point, boiling point, solubility, density, odor, and color. physical change would be liquid to solid or cutting a brick of salt etc. no change in composition of matter
Molecular bonds are made from overlapping atomic orbitals. What kind of bond do you get when parallel p-orbitals on adjacent atoms share electron density?
Pi bond.
What is pitch?
Pitch is our perception of the frequency of a sound. Each frequency will have its own pitch.
How does pH relate to gibbs free energy
Plug in Ka or Kb into -RTln(keq). According to the data from Table 1, as the temperature increases, the pH decreases ([H+] increases), and Ka increases. This corresponds to a decrease in ΔG° (ie, a more negative ΔG°). Therefore, ΔG° at pH 2.0 is less than ΔG° at pH 2.6.
What are dipole-dipole interactions? In what phases do they matter?
Polar molecules share electrons unequally in their bonds, and therefore have areas of partial negative charge and areas of partial positive charge. In dipole dipole interactions, the positively charged region of one molecule will attract to the negatively charged region of another molecule. These dipoles are not temporary, like in London Dispersion forces, and so the dipole-dipole interaction is much stronger. neglidgible in gas phase because molecules are far apart
Nucleophile/electrophile reactions require what type of solvents?
Polar, nonpolar are ass
What is important to remember about polyprotic acids?
Polyprotic acids are acids with multiple protons. This means that 1 mole of a polyprotic acid will dissociate into more than 1 mole of protons. It is important that we account for this difference in ka calculations, neutralization reactions, etc.
Double slit interferance equation
Position of the minima (dark spots) can be found by: dsin(theta)=(n+1/2)lambda d is distance between two slits theta is the line drawn from the midpoint of the two slits to the dark fringe and the normal n is an integer indicating the number of the fringe theta is the wavelength of the incident wave Note: bright fringes are halfway between dark fringes
What is galvanization/ plating
Precipitation onto cathode (when Cu2+ binds to cathode)
What is pressure?
Pressure is force applied over an area.
What are the 4 variables that define the state of a gas?
Pressure, Volume, Temperature, and the number of moles of gas.
Primary alcohlols can be oxidized by strong oxidizers (like CrO3 or Na2Cr2O7) to form [aldehydes, ketones, or carboxylic acids?]
Primary alcohlols can be oxidized by strong oxidizers (like CrO3 or Na2Cr2O7) to form carboxylic acids
Primary alcohlols can be oxidized by weak oxidizers (like PCC) to form [aldehydes, ketones, or carboxylic acids?]
Primary alcohlols can be oxidized by weak oxidizers (like PCC) to form aldehydes
How do primary alcohols interact with oxidizing agents?
Primary alcohols are readily oxidized to Carboxylic Acids by basically every single oxidizing agent except PCC which is very weak. PCC will only oxidize a primary alcohol to an aldehyde. Look for chromium and permanganate as oxidizing agents! The KMnO4 one is straight wrong. It oxidizes all the way
What side of the reaction is heat on in an exothermic reaction?
Products side.
Polar protic vs aprotic solvents favoring Sn1 vs Sn2
Protic- Sn1 aprotic- Sn2
What is pyrophosphate?
Pyrophosphate is the name of phosphate dimers. It is denoted PPi in biological contexts. This is released when nucleotides come together and form phosphodiester bonds. This will dissociate into inorganic phosphate in solution
What is the formula for Capacitance?
Q is the magnitude of the charge on either of the plates (they will be the same just opposite sign)
What is a quinone?
Quinones are the product of the oxidization of phenols. They are characterized by a ring systems with carbonyls. Some quinones are aromatic, but not all of them. Resonance stabilized electrophiles Serve as electron acceptros. Vitamin K1 (phylloquinone) is an examoke as well as vitamin K2 (menaquinones)
What is R and S absolute configuration?
R and S absolute configuration is a way of describing the configuration of a chiral center in a molecule without referring to something else to do so. In order to do this, one must complete a multi step process. Make sure you practice the process before test day.
Do the R/S and D/L systems describe relative or absolute configuration
R/S is describing the absolute configuration of each chiral center D/L describes the relative config as compared to + and - glyceraldehyde. If it has same config as + glyceraldehyde then it is D and viceversa. However, being D doesnt also mean it is +, it could be -
At equilibrium, as concentration of products increases, concentration of reactants _____
Reactants decrease (because forming products) Careful with wording, the question doesn't say we are adding products (in which case concentration of reactants would increase)
What is reaction coordinate?
Reaction coordinate is the x-axis of coordinate diagrams. It's just a weird way of saying how far into the reaction you are. This is usually seen on thermodynamic graphs.
What are reaction diagrams?
Reaction diagrams are graphs that track a thermodynamic property of a reaction over time. These graphs usually measure free energy change with respect to coordinate, enthalpy change with respect to coordinate, or entropy change with respect to coordinate.
Reaction quotient vs Equilibrium constant
Reaction quotient is concentration of reactants and products at any time during reaction and Eq constant is concentrations at equilibrium
What are real gases?
Real gases are the gases that actually exist in the universe. These are different from ideal gases in that they occupy volumes and exhibit intermolecular forces.
Describe a nickel- cadmium battery
Rechargeable. Solid cadmium is the anode and nickel (III) oxide hydroxide is the cathode, connected by KOH Discharge: galvanic Oxidation half reaction for cadmium (negative) anode: Cd (s) + 2OH- (aq) -> Cd(OH)2 (s) + 2e- Reduction half reaction at the nickel oxide hydroxide (positive) cathode: 2NiO(OH) (s) +2H2O +2e- -> 2Ni(OH)2 (s) +2OH- Charging: electrolytic, reverses cell potentials Higher energy density than lead acid batteries Provide good surge current (periods of large current early in discharge cycle) Widely replaced by nickel-metal hydride (NiMH) batteries due to higher energy density, cost efficiency, and less toxicity
What is recrystallization?
Recrystallization is a method for further purifying crystals in solution. In this method, we put our product in a small amount of solvent so that it is close to dissolving, but not quite there yet. Then, we slowly heat the solvent, which increases the solubility enough to make the product dissolve. Finally, we slowly cool the flask, which causes the product to slowly crystalize out of the solution on its own with no impurities.
Redox reactions always happen [in isolation or in pairs?]
Redox reactions always happen in pairs
What are some good reducing agents (in orgo)?
Reducing agents get oxidized themselves, and therefore will have features that make them unattractive to electrons. Two main examples would be low electronegativity (sodium, magnesium, zinc, aluminum, zinc). Note: NaBH4 ccannot reduce carboxylic acids And negative charge on an atom, usually the Hydride ion (H-) which comes from metal hydride reagents like LiAlH4 (This can oxidize ester to a pair of alcholos and aldehydes/ketones/carboxylic acids to alcohol and amides to amines)
What is reflection?
Reflection is the tendency of a wave to bounce backwards when it encounters a boundary between two media. These media can be anything as long as they are different, oil and water, air and glass, etc.
What is refraction?
Refraction is the bending of light as it passes from one medium to another and changes speed.
What is relative vs absolute configuration?
Relative configuration is the configuration of a chiral molecule as it relates to another molecule. It doesn't tell you something specific to the molecule, instead it tells you how it is different from some other molecule. If a molecule undergoes a reaction and the bonds of the stereocenter aren't broken (so position of groups around chiral carbons remains the same), relative configuration remains the same. IF position changes (like in sN2 reactions), then the substrate and product will be enantiomers/ diasteromers and thus the relativve config will have changed Examples of relative configurations include: saying something is an enantiomer of something else, saying something is a diastereomer of something else, etc. Absolute configuration describes the exact spatial arrangement of these atoms or groups, independent of other molecules
How do resonance structures affect the formal charges on atoms in a molecule?
Remember that the real molecule is a hybridization of its resonance structures. So for example, if there are two resonance structures of equal stability and one in one of them the formal charge on an atom is -1 and in the other the formal charge is 0, then the overall formal charge will be the average, -1 + 0 / 2 = -1/2
What is the critical angle?
Remember that when light travels from a high index of refraction to a low index of refraction, it bends away from the normal. If you shine light with the right angle, you can actually bend light in such a way that it's angle of refraction is equal to 90 degrees, which means the light just travels along the boundary of the materials instead of refracting from one to the other. The incident angle required to make the light bend in this way is called the critical angle.
What is normality (N)?
Remember when you learned that sometimes 1 mole of a molecule can be made up of more than one mole of a certain atom? For example, 1 mole of H2O is made of 2 moles of H and 1 mole of O? Well, normality is a way to account for this difference in the molecule and the atoms into which it could potentially split up. Normality is like Molarity, in that it is measured in moles per liter. But, Normality is not the moles of the substance itself per liters. Instead, Normality is the moles of what we are interested in per liters. In the below example, we are interested in Hydrogen ions. Notice how 3 different compounds at the same molarity, 1M can have very different Normalities due to their differential contribution of hydrogen ions to the solution.
What is total internal reflection?
Remember, at the critical angle, the light that is being refracted is being bent all the way to the boundary of the two materials. If the angle of incidence is even higher than the critical angle, all refracted light will end up on the same side of the boundary, which is to say that it is actually being reflected. Therefore, total internal reflection is when you refract the light at such a wide angle that it just ends up reflecting. This happens when the angle of incidence for the light wave exceeds its critical angle.
How do we use dimensional analysis to convert things?
Remember, dimensional analysis is just recognizing the basic quantity associated with the number and the specific unit of measure associated with the number. Once we see the basic quantity and the unit of measure, we can combine it with a conversion factor to convert it into a different unit of measure (but never a different basic quantity). These conversion factors must be memorized and then combined used in such a way so as to cancel out the starting unit of measure and result in only the new unit of measure.
What is meant by ideal bond angle?
Remember, each atom in a molecule has positive and negative charges associated with it. This means that, certain arrangements of the atoms will result in higher/lower electrical potential energies. The molecule will always adopt the most stable configuration, which is the configuration with the least amount of electrical potential energy. This most stable configuration is described by the ideal bond angle. For example, in a molecule with 4 bonded pairs and no unbonded pairs, the lowest potential energy is associated with all the atoms being arranged in a tetrahedron, which has an ideal bond angle of 109.5
How do we name ionic compounds?
Remember, ionic compounds will always have a cation and an anion. 1. Write the cations name as is (Unless it is an element that can form more than one stable positive ion, in which case you denote what its charge is with parentheses and roman numerals. 2. Write the anion's name. If it is a monoatomic (One type of atom, O2-, F-) anion drop the ending of element and add -ide. If it's a polyatomic ion, just write the polyatomic anion's memorized name.
How does one determine whether an atom's ion will be bigger or smaller?
Remember, the electrons are what determine the overall size of the atom. Therefore, if an atom loses electrons to become an ion (like the metals), it will have a smaller ionic radius than atomic radius. On the other hand, if an atom gains electrons to become an ion (like the non-metals), it will have a larger ionic radius than atomic radius.
What is resonance?
Resonance is a phenomenon in which electron density is spread around a molecule due to the presence of conjugated bonds. This is most often symbolized by drawing different versions of the molecule in which the double bond is in different locations, although in reality, the double bond is actually spread out across all the locations. There isnt an equilibrium between types of resonance structures present. There is only one form present, the hybrid. The hybrid can more closely resemble one of the resonance structures, but it will still be the only "thing" present. Meaning in the diagram below you wouldnt actually see these three. you would see a combination of them all.
How does resonance affect molecules?
Resonance spreads electrons out, which reduces the internal repulsion of a molecule, which makes it much more stable! This phenomenon is very powerful and actually has its own name, resonance stabilization.
Which is more important when determining stability: Resonance (from conjugation) or induction
Resonance!!
What is resonant frequency?
Resonant frequency is the natural frequency or frequencies at which an object vibrates. Any solid object, when hit, struck, rubbed, or disturbed physically in any way, will begin to vibrate.
What is reverse-phase chromatography?
Reverse-phase chromatography is basically identical to other forms of thin layer chromatography. The only difference is that the stationary phase is nonpolar and the mobile phase is polar. THus, polar things travel farther. In normal TLC, it's the other way around.
A reaction stops just before all reactants are made into products, is it reversible or irreversible and what's true about the forward and reverse rates?
Reversible because not all possible product was made. Forward and reverse rates are equal because its at EQ ****************************
What is ring strain?
Ring strain is the instability introduced into a molecule by the formation of a ring. It has its own name, but its really just a combination of angle, torsional, and steric (nonbonded) strain that occurs when you cyclize molecules in certain ways. For the figure below, remember more energy means more unstable.
Entropy in terms of microstates
S=k[ln(W)] k is boltzmanns constant and W is number of microstates
What is standard temperature and pressure (STP)?
STP is 0 degrees celsius (273K) and 1 atm. This is different than standard conditions! STP is used for ideal gas calculations.
What is STP?
STP is standard temperature and pressure. It refers to conditions of 273 K (0C) and 1 atm. Note this is not the same thing as standard conditions!
If we have a spring and we put two blocks with different mass on it, and compress the spring and let it release, which block will go higher?
Same height!
A positive test charge will move in the ____ direction as the vector field lines
Same, and thus have positive force. If it is negative test charge it will experience force opposite the vector field lines. (negatives move against the arrows)
Secondary alcohlols can be oxidized by oxidizers to form [aldehydes, ketones, or carboxylic acids?]
Secondary alcohlols can be oxidized by oxidizers to form ketones
How to calculate radius of circular motion for a charge released in a field
Set centripetal force equal to magnetic force!
Describe the C=O IR peak
Sharp peak around 1750cm-1. Usually pretty tall as well.
What is shielding?
Shielding refers to how much electron density is on a proton. So electron donating groups increase shielding whereas electron withdrawing groups decrease shielding. Generally, the less shielding, the farther the chemical shift associated with that proton. This means hydrogens attached to or adjacent to electronegative atoms usually have higher chemical shifts. Thus it makes sense why TMS is a zero, the silicon donates so much that there is nothing more shielded (to the right) than it MNEMONIC: Deshielding moves the proton Downfield (to the left)
Molecular bonds are made from overlapping atomic orbitals. What kind of bond do you get when orbitals overlap directly?
Sigma (or single) bonds.
Describe the relative strength of sigma bonds compared to pi bonds.
Sigma bonds, because they are a product of actual overlap between atomic orbitals, are much stronger than pi bonds. sigma has more overlap Note, a double bond is stronger than a sigma bond because a double bond has a sigma bond AND a pi bond, but the sigma bond is still providing most of the bond energy.
What type of bonds allow for free rotation of the atoms that make up the bond.
Sigma. Remember, a pi bond is made from the overlap of electron density between two parallel pi bonds. If you try to rotate one of the atoms, you will start to disrupt the bond. The electrons prefer being in the bond to floating around randomly, so they will resist your attempt to rotate the pi bond.
How to read mass spec
Signal intensity of a mass spectrometry peak corresponds to the relative quantity of ions at a given mass-to-charge ratio m/z. Increased charge yields a decreased m/z ratio; therefore, an increase in the number of multiply charged particles increases signal intensity at lower m/z ratios THis would cause a left shift
Describe the bond strength of single, double, and triple bonds.
Single bonds, with their one sigma bond, are weakest. Double bonds, with their one sigma bond and pi bond, are in the middle. Triple bonds, with their one sigma bond and two pi bonds, are the strongest.
How does radius relate to pressure required to counter surface tension
Smaller radius= higher pressure to counter surface tension. Thus, two connected alveoli that lose surfactant will combine to one big alveoli to reduce the amount of pressure needed to prevent collapse
Describe Sn1 Reactions
Sn1 reactions contain two steps. In the first step (the rate limiting step) the leaving group leaves, generating a positively charged carbocation (great electrophile!). In the second step, the nucleophile attacks the carbocation.
Sn2 reactions result in [inverted stereochemistry or racemic mixtures?]
Sn2 reactions result in inverted stereochemistry Note: this always inverts relative configuration Note: if the nucleophile and leaving group have same priority in their respective molecules then R will switch to S (absolute config) Note: absolute config DOES NOT always switch
How do d and l relate to R and S?
So, R and S are enantiomers of eachother. So are d and l. But d doesn't necessarily mean R, and l doesn't neccessarily mean l. d and l have to be experimentally determined while R and S can be determined by just looking at a molecule. So, if the d enantiomer ends up being the R enantiomer, then the l enantiomer will be the S enantiomer. But if the d enantiomer ends up being the S enantiomer, then the d enantiomer will be the R enantiomer.
What is the solubility product?
Solubility product is just a special form of an equilbrium constant. It describes the equilibrium of a solid dissolving into its constituent ions. You find it using the normal rules for equilibrium expressions. Concentrations that you plug in are equilibrium (saturation) concentrations For molar solubility this would be (3x)3(2x)2=108x5 where x is molar solubility of Ca3(PO4)2
What is solvation a.k.a dissolution?
Solvation is the electrostatic interaction between solvent and solute molecules that causes ions to be separated from one another in solution.
How does solvation occur?
Solvation occurs when the electrostatic interactions between the solvent and the solute are strong enough to break the intermolecular bonds in the solute and separate the ions from one another.
What is sound?
Sound is a longitudinal wave that transmits through the oscillation of particles in a deformable medium. As such, sound can travel through solids, liquids, and gases.
Sound waves are [longitudinal or transverse?] waves
Sound waves are longitudinal waves
Describe a concentration cell
Special type of galvanic cell. Contains two half cells connected by a conductive material that allows a spontaneous reaction to occur. However, both electrodes are chemically identical. For example both are copper metal, so both have same reduction potential. Thus, current is generated as a function of concentration gradient. The gradient results in a potential difference that drives the movement of electrons in a way that brings equilibrium. Thus, the voltage/ electromotive force is Zero when concentrations are equal. Example is a cell membrane!!
What is specific rotation?
Specific rotation is the amount a compound rotates light per concentration of the molecule and length of the tube through which the light passes. Constant regardless of concentration at any given temp
What is spin-spin coupling?
Spin-spin coupling, aka peak splitting, is a phenomenon seen when nonequivalent protons are attached to adjacent carbons. (DONT include H attached to oxygen or nitrogen)Depending on the number of adjacent carbon bound hydrogens, peaks will be split up into pieces. Remember, the Spectrum for the red H on any of these would only have two split peaks because the only ADJACENT carbon is the blue one. Red vs. blue would make different peaks, rember that
What does it mean to have a staggered newman projection?
Staggered newman projections occur when the substituents are not lined up with one another. These can either be in anti or gauche conformation. Low energy, high stability
In closed pipes, what harmonics are standing waves limited to?
Standing waves in closed pipes are limited to odd harmonics. This is because the standing wave in a closed pipe has to have a node at one end and an anti node at another end, and this is only possible with odd harmonics.
What is steric strain?
Steric Strain (nonbonded strain or van der waals repulsion), also referred to as steric hindrance, Steric strain is resulting from the fact that bulky substituents occupy large space around a carbon atom which will result in getting the substituents closer to each other, and therefore, their electrons will be repelling
What is steric protection?
Steric protection is the process of protecting a functional group of interest from further reactions by converting it into a temporary protecting group that is sterically hindered or unreactive in the following reactions.\ Ex. SN2 cant react on tertiary carbons Ex. Alcohols may be protected by converting to tert-butyl ethers
Adding bromine onto the alpha carbon of a carboxylic acid
Substitution of bromine on the ╬▒-carbon of a carboxylic acid, known as the Hell-Volhard-Zelinsky (HVZ) reaction, begins with the addition of PBr3. This step converts the carboxylic acid to an acyl bromide, which can then tautomerize from the keto form to the enol form. When Br2 is added to the reaction, the enol form of the acyl bromide acts as the nucleophile and attacks bromine. One of the bromine atoms in Br2 withdraws electrons away from the other, giving it a partial positive charge and making it a good electrophile. The electrophilic bromine is added to the ╬▒-carbon, forming an ╬▒-bromo acyl bromide and HBr. Finally, when water is added, it attacks the electrophilic carbonyl carbon, and the bromine on the carbonyl carbon acts as the leaving group. This yields an ╬▒-bromoacid, which is a useful intermediate in the synthesis of ╬▒-amino acids such as valine.
How can we calculate the standard gibbs free energy for a reaction?
Subtract the sum of the standard gibbs free energy of the products by the sum of the standard gibbs free energy of the reactants. or deltaG=deltaH-TdeltaS equation but with standard H and S
What does a second order reaction suggest about the reaction
Suggests a physical collision between two molecules, especially if the rate law is first order with respect to two reactants
What is superheating?
Superheating is when a liquid is heated to a temperature above its boiling point without vaporizing. Superheating occurs when gas bubbles within a liquid are unable to overcome the combination of atmospheric pressure and surface tension. This is fixed in distillations by adding boiling chips, ebulliators, or magnetic stir bars to the distilling flask.
Swapping two pairs on a fischer projection or rotating 180 degrees will [how is the sterochemistry affected?]
Swapping two pairs on a fischer projection or rotating 180 degrees will retain the stereochemistry This is equivalent to rotating the fischer projection 180 degrees.
How does one calculate the average velocity of an object?
Take the change in (displacement) and divide it by the change in time.
Thermal energy content vs temp
Temp is average kinetic energy of molecules in that substance Thermal energy takes into acccount amount of substance So lots of lukewarm water will have higher thermal energy than a small amount of hot water, even though the hot water has higher temp
What is the SI unit for magnetic field strength?
Tesla
What is the fischer esterification?
The Fischer esterification is a reaction in which carboxylic acids are activated by acid and reacted with alcohols to produce esters. This mechanism follows the normal nucleophilic acyl substitution mechanism.
The Gabriel Synthesis results in a [racemic mixture or stereoselect product?]
The Gabriel Synthesis results in a racemic mixture Both L and D isomers are created
What are the reactants and products of the Gabriel Synthesis?
The Gabriel Synthesis uses a cyclic molcecule called Phthalamide (usually as potassium phthalimide) and Diethyl Bromomalonate in the presence of base to generate a highly substituted carb-anion intermediate. This is mixed with an R-Br (any good leaving group of choice) and treated with acid to make an amino acid.
What is the HOMO?
The HOMO is the Highest Occupied Molecular Orbital. This is the highest energy level at which the electrons naturally sit.
What is the Heisenberg Uncertainty Principle
The Heisenbergy Uncertainty Principle states that it is impossible to determine the momentum and position of an electron simultaneously. This is because focusing on the momentum of the electron makes it harder to know the position, and vice versa.
Of the three acid definitions, which is the most general?
The Lewis definition is the most general definition of acids/bases, followed by the bronsted lowry and then the arrhenius.
What is the Nernst Equation?
The Nernst Equation allows us to determine the E cell of a battery at non standard conditions.
What is the Pauli Exclusion Principle?
The Pauli exclusion principle says that no two electrons in a given atom can posess the same set of four quantum numbers. Specifically, this means that electrons in the same orbital must have opposite spins in order to be unique.
What is the effective nuclear charge?
The actual attraction that outer electrons feel from the nucleus when you account for shielding.
What is the actual yield?
The actual yield is the amount of product an individual actually obtained after completing the reaction. This amount will always be lower than the theoretical yield due to errors/side reactions/loss of products/incomplete collection of product, etc.
What is the adsorbent?
The adsorbent is just another word for the stationary phase in a chromatograph.
Describe the second step of the aldol condensation
The aldol generated in the first step is treated with strong base and high temperatures, which generates an unsaturated alpha beta carbonyl. The aldol condensation is useful for lengthening carbon chains on carbonyl containing compounds. This second step is a dehydration reaction ELIMINATION produces an alpha,beta-unsaturated carbonyl
Describe the second step of the Strecker Synthesis
The aminonitrile generated in the first step is protonated to activate it for nucleophilic substitution. Next, a water molecule attacks the nitrile group to form an Imine. The attached water deprotonates to an alcohol and transfers the proton to the imine, activating it for another substitution by water. The second water attack results in a compound with a water, alcohol, and amino group on the same carbon. The attached water deprotonates to an alcohol and transfers the proton to the amino group, activating it as a leaving group. One of the hydroxyl groups forms a carbonyl and kicks the amino group off. The Carbonyl deprotonates, resulting in an amino acid. Carried out in aqueous acid and can be accelerated with heat
The amount of current produced by the photoelectric effect is directly proportional to the [...] of the incident light.
The amount of current produced by the photoelectric effect is directly proportional to the intensity of the incident light.
Describe electric potential energy relation to work?
The amount of work necessary to bring a charge from infinity to that point. Two like charges will have potential energy become increasingly positive as they get closer and two unlike charges will have potential energy become increasingly negative as they move closer (more stable) So opposites moving together and like charges moving apart will DECREASE electric potential energy.
What is the atomic mass of an atom?
The atomic mass of an atom is its mass number minus the mass lost in the form of binding energy. However, the mass lost to binding energy is so small that the atomic mass and the mass number are basically the same.
What is binding energy and which elements have highest binding energy
The bonded protons and neutrons of a nucelus are at lower energy than if they were unbonded. Where does this energy go? released as heat, light, other electromagnetic radiation. This energy is the binding energy. Binding energy peaks at iron implying it is the most stable. Intermediate sized nuclei are more stable than very large or very small.
What are the characteristic physical properties of aldehydes and ketones?
The carbonyl carbon contains a decently strong dipole (actually stronger than that of alcohols) due to oxygen's higher electronegativity when compared to carbon. This results in increased intermolecular forces, which leads to higher boiling points and melting points. However, because there is no hydrogen on the oxygen, aldehydes and ketones can interact through hydrogen bonds with themselves, which means there intermolecular forces aren't as high as alcohols and carboxylic acids. Aldehydes and ketones are polar, but not that polar, so their solubility in water is variable depending on how long the carbon chain is. Of the two, aldehydes are generally the better electrophiles.
How can you generally describe the reactions of aldehydes and ketones?
The carbonyl carbon is a good electrophile, so most of the reactions involving aldehydes and ketones involve nucleophilic substitution at the carbonyl carbon. The bond to the nucleophile displaces one of the bonds to the oxygen and pushes it up as a lone pair on the oxygen. If a good leaving group is present the double bond will reform and kick off the leaving group (like with carboxyllic acid and their derivatives) or the negative can just take a proton and be happy as an OH as seen below(aldehydes and ketones)
What is the first law of thermodynamics in the context of Thermodynamics problems?
The change in the total internal energy of a system must be equal to the change in heat and work (because energy must be conserved). Q-W energy transfered in as heat minus work done by the system
What should the change in total mechanical energy of an object be equal to when considering nonconservative forces?
The change in total mechanical energy will be equal to the work lost due to the nonconservative forces.
What does it mean if a thermodynamic property is written with a degree sign (prime) or called "Standard"
The changes in enthalpy, entropy, and free energy that occur when a reaction takes place under standard conditions are called the standard enthalpy, standard entropy, and standard free energy changes, respectively, and are symbolized by ΔH°, ΔS°, and ΔG°.
The closer field lines are the [...] the field is.
The closer field lines are the stronger the field is. Note that field lines for a single charge never cross
What is the Collision Theory of Chemical Kinetics and equation?
The collision theory states that, for a reaction to occur, the molecules must collide with eachother in appropriate configurations. Therefore, the rate of a reaction is proportional to the number of collisions per second between the reacting molecules. rate=Z*f Z= number of collisions, f= fraction of collisions that are effective
How do the components of vectors add when two overall vectors are summed?
The components themselves simply sum.
What happens if the solute-solvent interactions are not stronger than the intermolecular forces in the compound?
The compound will not dissolve.
What principle explains all the circuit laws?
The conservation of energy principle.
Describe the continuity equation?
The continuity equation states that the flow rate must be equal at all points in the pipe, regardless of changes in cross-sectional area.
What is the coupling constant?
The coupling constant, j, is a measure of how widely split peaks get when they split. This constant is unique to basically every splitting situation.
What is the critical point?
The critical point marks the boundary of pressure and temperature at which you will still see normal phases. After the temperature and pressure exceed that of the critical point, the substance becomes a supercritical fluid with gaseous and liquid properties.
What physical properties affect capacitance?
The cross sectional area of the plates and the distance between them.
What is the Junction Rule?
The current going into a junction must be equal to the current going out of a junction.
How do dielectrics affect capacitors connected to a voltage source (battery)?
The dielectric will reduce the electric field in the capacitor, which would normally lead to a decrease in voltage, but the capacitor is hooked up to an external voltage source, so it maintains its voltage. Instead, the decrease in the electric field in the capacitor will manifest itself as an increase in the charge on the plates of the capacitor.
What happens when a dipole is placed in an electric field?
The dipole will spin if necessary in order to cancel out its torques. An example is shown below. Initial Final
When bringing two charges together, work is equal to
The electric potential energy of the system! it will be pos if the charges are the same and neg if they are different (because they want to go together) If the overall work is negative the charges are in a more stable position than before
What is the electro-motive force?
The electro-motive force is the potential difference between the two terminals of a cell. This potential difference is what drives the electrons through the wire of the circuit. Notice that this is not a force, but a potential difference. The name is a misnomer. Has units of volts (J/C)
What happens when two liquids at different temperatures mix?
The energies of the liquids will be added together and distributed evenly to the total mixture. Basically, the total energy will be the same before and after.
How does one find the enthalpy of a reaction using only bond dissociation energies?
The enthalpy of the reaction will be equal to the energy it absorbed by breaking bonds minus the energy it released by forming bonds. going from solid to gas counts in total energy absorbed (bonds broken)
What is the third law of thermodynamics?
The entropy of a perfectly organized crystal at absolute zero is zero. This really means that there can be no temperature lower than absolute zero.
What happens if you shine light on a metal that has a higher energy than the work function energy?
The extra energy is converted into kinetic energy for the electron. So, the higher the frequency of the light shined on a metal, the higher the kinetic energy of the ejected electrons.
What makes music sound like music and not like noise?
The fact that the multiple frequencies at which the object vibrates are related to eachother by whole number ratios instead of just being randomly related.
The first overtone is the [...] for open systems and 3rd harmonic, given by n=3 for closed systems
The first overtone is the second harmonic, given by n=2 for open systems and 3rd harmonic, given by n=3 for closed systems Has 1/2 the wavelength and twice the frequency of the first harmonic
The first overtone is the second harmonic, given by n=2 for open systems and [...] for closed systems
The first overtone is the second harmonic, given by n=2 for open systems and 3rd harmonic, given by n=3 for closed systems Has 1/2 the wavelength and twice the frequency of the first harmonic
When thickness of a lens is ignored, how do we determine the sign of the focal length and radius
The first surface the light passes through (whether it is concave or convex)
The flow of heat from an object with a high temperature to an object with a low temperature is [...]
The flow of heat from an object with a high temperature to an object with a low temperature is spontaneous
How does one calculate the focal distance?
The focal distance will always be half the distance of the radius of curvature. f=R/2 Thus we can find focal point from this
What is the focal point?
The focal point is the point at which light rays parallel to the mirror or lens are focused (or virtually focused in the case of negative focal lengths)
What is air resistance?
The force of friction with the air. This force opposes movement and increases as speed increases, causing an object to reach a terminal velocity.
What is static friction?
The force that exists between a stationary object and the surface upon which it rests.
What is the purpose of the four quantum numbers?
The four quantum numbers exist so we can quickly and easily describe every electron's position in the atom. For example, if I assign the quantum numbers 2, 0,0,1/2, I know exactly which electron I am talking about: the electron in the second energy level, in the s orbital, in the up spin configuration.
What is standard free energy of formation
The free energy change that occurs when 1 mol of a compound in its standard state is produced from its respective elementss in their standard states under standard state conditions
When a light ray refracts from one medium to another, how does its frequency change?
The frequency of light is unaffected by refraction.
What is the fundamental frequency of a string?
The frequency of the first harmonic standing wave (n=1)
What is the standard enthalpy of combustion?
The heat associated with combusting something at standard conditions under constant pressure.
What is enthalpy of fusion?
The heat associated with fusion (going from solid to liquid) under constant pressure.
What is the henderson hasselbalch equation?
The henderson-Hasselbalch equation is used to estimate the pH of a buffer solution. For a weak acid buffer solution: (conjugate base/weak acid) And for a weak base buffer solution: (conjugate acid/ weak base) Remember this gives pOH so to get pH we need to convert
The higher the frequency of electromagnetic radiation, the higher its [...]
The higher the frequency of electromagnetic radiation, the higher its energy
The higher the temperature, the [faster or slower?] gas particles move.
The higher the temperature, the faster gas particles move.
What is the Ion Product (IP)?
The ion product is the state of the dissolving equilibrium at any given point. It can be compared to the ksp to determine whether or not the solution will precipitate. It is calculated in the same manner as Ksp. Analogous to reaction quotient, you plug in the concentrations at any point in time When greater than Ksp there will be precipitate
What is the kinetic molecular theory?
The kinetic molecular theory is a series of assumptions that is used to explain the behaviors of gases. These assumptions makes it possible to derive the ideal gas laws.
The kinetic molecular theory states that heavier gases diffuse and effuse [faster or slower?] than lighter gases.
The kinetic molecular theory states that heavier gases diffuse and effuse slower than lighter gases.
When using and analyzing newman projections, which substituents are the most important?
The largest ones. This is because we use the largest substituent's angle from one another to determine the conformation of the Newman Projection
Where are metals found on the periodic table?
The left side and the middle.
Double and triple bonds span 2 carbons, so which one do we use to name them?
The lower number one. For example, a double bond that spans carbons 2 and 3 would be named -2-ene
How do HOMO and LUMO relate to spectroscopy
The lower the energy gap between HOMO and LUMO, the more easily molecules are excited and thus they absorb longer wavelengths and lower frequencies with lower energy.
What is the absolute lowest dielectric constant and to what material does it belong?
The lowest dielectric constant is 1 and it belongs to vacuum, which is when there is absolutely nothing between the plates of a capacitor. The dielectric constant for a material will ALWAYS be higher than this value, and never lower. There are no negative or less than 1 dielectric constants.
How can there be a range of static frictions?
The magnititude of static friction depends on factors like the amount of surface area in contact (more = higher).
What is the number following the element name when describing an isotope?
The mass number. For example. Carbon-12 has a mass number of 12.
What is mass defect
The mass of every nucleus is smaller than the sum of protons and neutrons because some mass is converted to energy. The mass defect is the amount of mass lost to binding energy Characterized by E=mc2 Notice a small amount of mass can yield a massive amount of energy
What is the molar solubility?
The molar solubility is the concentration of an ion in molarity in its saturated solution.
Why does surface tension occur at the surface?
The molecules in a liquid experience an attractive force with one another known as cohesion. Under the surface of the liquid, each molecule is completely surrounded by other liquid molecules. This results in the cohesion forces being felt in all directions, causing them to cancel out. At the surface, on the other hand, molecules are only experiencing cohesion forces from beneath them. This causes the molecules at the surface of the liquid to be pulled inward, leading to the tension force at the surface.
How do the moles of a molecule relate to the moles of the atoms that make it up?
The moles of a molecule are related to its subsitituent atoms by their subscripts. For example, one molecule of H2O is comprised of 1 oxygen and 2 hydrogens. Therefore, to make 1 mole of H2O I would need to collect 1 mole of Oxygen and 2 moles of Hydrogen, and combine them together to make 1 mole of H2O. Notice that there are 2 moles of Hydrogen in 1 mole of H2O because H2O explicitly calls for twice as many hydrogens than oxygens.
During a titration with strong base/acid, what info is required to find the mols of sample? concentration of sample?
The moles of sample only requires the moles of the titrant and the volume used. Since it is strong acid/ base we assume one mol added will protonate/deprotonate one mol of sample. IF we want concentration of original sample we need its volume.
The more conjugated a system, the [higher or lower?] the wavelength at which it will absorb UV light?
The more conjugated a system, the higher the wavelength at which it will absorb UV light? Note: remember higher wavelength means lower frequency. Some very conjugated large molecules may absorb visible light, leading to color
What is the normal force?
The normal force is a contact force that keeps objects from passing through one another. The normal force is perpendicular to the plane of contact between two surfaces.
How must a nucleophile and a leaving group be related for an Sn2 reaction to proceed?
The nucleophile has to have a stronger affinity for the electrophile than the leaving group, otherwise the leaving group won't leave and the nucleophile won't be able to attack.
What is NMR spectroscopy?
The nucleus of an atom, when placed in a magnetic field, can be aligned with the magnetic field (alpha state, less energy) or unaligned (beta state, higher energy). The difference in energy between these two states depends on the type of atom and the types of atoms around it. What we do is we put molecules in heavy magnetic fields and then shine different frequencies of light to see which ones they absorb (this shifts some from alpha state to beta state). Depending on the types of absorptions we see in the NMR read out, we can determine the types of atoms in the molecule, and determine its overall structure.
What is period?
The number of seconds it takes a wave to complete one oscillation. Represented by a capital T.
What is the rule that describes the way atoms join to form compounds and what does it state?
The octet rule. The octet rule states that to have a full octet of electrons in the outermost shell is the most stable state for an atom, and atoms will give/take/share valence electrons in such a way so as to ensure that both (or more) atoms in the compound have noble gas configurations
What is the order in terms of kinetics?
The order is the number a reactant is raised to. Remember, the order of the reactant must be experimentally determined. The balanced equation will not predict the order.
What is the overall order of a reaction?
The overall order of a reaction is just the sum of the orders of the individual reactants.
What is unique about the phase diagram for water?
The phase diagram for water has a negative slope for the solid<>liquid equilibrium line. This is out of the ordinary. Almost every phase diagram will only have positive slopes on its equilibrium lines. This is due to the hydrogen bonds in water and how they space out the crystalline structure of ice.
Describe the physical and chemical properties of enantiomers?
The physical and chemical properties of enantiomers are basically equivalent, except in the case of two important exceptions. 1. Optical activity 2. Reactions in chiral (biological and natural) environments. For example, a lot of enantiomers of normal molecules like glucose and proteins can be toxic to humans.
Explain how something like pressure is a state function.
The pressure in a system is defined only by the current equilibirum state of the gas particles. Take for instance, 2 balloons with a pressure of 1 atm each. The pressures in these balloons are identical. It does not matter if the first balloon came to 1atm from 10atm and the second balloon came to 1 atm from .01atm. The fact of the matter is that, right now, their pressures are both 1atm.
What is the principle of superposition?
The principle of superposition states that when waves interact with eachother, the displacement of the resultant wave will be equal to the sum of the displacements of the two interacting waves. This means waves add when they have the same sign and they subtract when they have opposite signs.
What is heat?
The process by which energy is transferred between two objects by virtue of their difference in temperature
The process of measuring transferred heat is called [...]
The process of measuring transferred heat is called calorimetry
What is the radius/center of curvature for a spherical mirror?
The radius/center of curvature is the distance to the center of the theoretical sphere that the mirror would make if it was a complete sphere.
What is power? (No calculation, qualitative)
The rate at which energy is transferred from one system to another.
The rate at which nuclei decay is [...] to the number of nuclei that remain
The rate at which nuclei decay is proportional to the number of nuclei that remain Aka as time goes on and less nuclei remain, decay will be slower Think: first half life gets rid of half whereas second half life only gets rid of 1/4 of the original total. These half lives are the same amount of time. So decay rate must have been fastest at the beginning since more decayed in an equal amount of time
How do we calculate the rate of a reaction?
The rate will always be equal to the rate constant of the reaction times the concentration of the rectants raised to experimentally determined exponents.
What is electric potential
The ratio of the magnitude of a charges electric potential energy to the magnitude of the charge itself
The reducing agent gets [oxidized or reduced?]
The reducing agent gets oxidized
What is spherical abberation
The result of the imperfections on mirrors and lenses. The result is the blurring of the periphery of an image as a result of inadequate reflection of parallel beams at the edge of a lens. This creates an area of multiple images with very slightly different image distaces at the edge of the image, which appears blurry
What is the retardation factor?
The retardation factor, Rf, is a way of identifying a molecule after it has been TLC'd. The retardation factor is equal to the distance a certain molecule moved over the total distance the whole solvent moved. The Rf is relatively constant for a particular compound in a particular solvent, and can therefore be used as a reference to identify compounds.
Describe the Retro-Aldol Reaction
The retro-aldol reaction is just the reverse of the aldol condensation. In this reaction, aqueous base and heat is applied to an aldol. The result is that the bond between the alpha and beta carbon breaks, resulting in two carbonyl containing compounds (can be any combo of ketone and aldehyde) . A retro-aldol reaction is the reverse of an aldol condensation. Either the aldol product (╬▓-hydroxy ketone) or the dehydration product (enone or enal) is heated and treated with base, causing the carbon-carbon bond between the ╬▒- and ╬▓-carbons to break. The retro-aldol reaction yields two products: either two ketones, two aldehydes, or one of each. The products depend on the substituents on the carbonyl carbon and the ╬▓-carbon. If the carbonyl carbon is bonded to a hydrogen atom before the reaction (ie, it was already an aldehyde), it will still be an aldehyde after the reaction. If the ╬▓-carbon is bonded to a hydrogen, it will become an aldehyde. If the carbonyl or ╬▓-carbon are not bonded to hydrogen, they will become ketones.
What is torque?
The rotational force that occurs when a force is applied to a lever arm on a fulcrum of some length.
What does it take for two compounds to be the "same"
The same set of atoms can bond in different ways. For two chemical species to be the same, both the elemental composition and the electronic bonding configuration must be the same. Same electrons, atoms, and bonding config
How does one calculate the wavelength and frequency of the standing wave in an open pipe?
The same way you do it for a string, except both ends are anti nodes instead of nodes. frequency is same too Where L is the length of the pipe and n is a non-zero positive integer known as the harmonic (corresponds to the number of half wavelengths on the string).
The second ionization energy will always be [...] than the first ionization energy, and so on.
The second ionization energy will always be larger than the first ionization energy, and so on.
The second overtone is the [...] for open systems and 5th harmonic, given by n=5 for closed systems
The second overtone is the third harmonic, given by n=3 for open systems and 5th harmonic, given by n=5 for closed systems
The second overtone is the third harmonic, given by n=3 for open systems and [...] for closed systems
The second overtone is the third harmonic, given by n=3 for open systems and 5th harmonic, given by n=5 for closed systems
What is a solute?
The solute is the compound you add to the solvent. In this example, the blue powder is the solute because it was a solid before mixing and in the liquid phase with water after.
What is the solvent front?
The solvent front is how far the solvent was allowed to travel overall in a TLC analysis.
What is the solvent?
The solvent is the component of the mixture that stays in the same phase after mixing. For example, water is the solvent because it was a liquid before mixing and after. If both remain in the same phase, the solvent is the one in greater quantity.
What is a source charge?
The source charge is the charge creating the electric field of interest.
What is a Daniell cell
The specific galvanic cell with zinc and copper bound to sulfate. Both zinc and copper ions are +2
What is specific gravity?
The specific gravity of a substance is the ratio of the substance's density to the density of pure water at 1atm and 4 degrees celsius. These paramaters are chosen because pure water has a density of exactly 1g/cm3 at them.
Shock waves have the greatest impact when the source is traveling at _______
The speed of sound. Above and below the shock waves are weaker
What is the standard enthalpy of formation?
The standard enthalpy of formation of a compound, ΔHfo is the enthalpy required to produce one mole of a compound from its elements in their standard states. For example, the standard enthalpy of formation of CO2(g) would be the enthalpy required to make one mole of CO2 from 1 mole of C(s) and 1 mole of O2(g)
How can we calculate the standard entropy of a reaction?
The standard entropy of a reaction will be equal to the sum of the standard entropies of the products minus the sum of the standard entropies of the reactants.
How does one calculate the equivalent resistance of resistors in parallel?
The sum of the inverses of the resistances will be equal to the inverse of the total resistance.
What are the symmetric molecular geometries and why are they important to know?
The symmetric molecular geometries are... 1. Linear 2. Trigonal Planar 3. Tetrahedral 4. Octahedral 5. Square Planar It is important to know these symmetric molecular geometries because their symmetry can cause their dipoles to cancel out. This means that, even if you have polar bonds in an atom, they could cancel out in a linear/trigonal planar/etc. configuration and result in a molecule that is, overall, non-polar. Square planar and octahedral are extra special in that they can have different atoms yet still be nonpolar, ex. XeF2cl2 will be non polar in the configuration that has each atom opposite to its pair CCl2H2 will alwyas be polar however since Cl and H can never be across from eachother
What is thermal expansion?
The tendency of objects to increase in size with increases in temperature.
What is half life?
The time it takes for half of a sample of radioactive particles to decay.
How does titration work?
The titrant is something you know the concentration, volume, and therefore moles of. You add the titrant to the titrand/analyte until a visible reaction of some sort is completed. This is usually the color change of an indicator in an acid/base titration. Once the color change occurs, you use how many moles of titrant you added to stoichiometrically determine how many moles of titrand/analyte were in the solution.
What is absolute (hydrostatic) pressure?
The total pressure that is exerted on an object that is submerged in a fluid. For objects on planets with an atmosphere, the absolute pressure will be comprised of the pressure on the object from the liquid in which it is submerged and the pressure on the object from the atmosphere.
How does one separate a racemic mixture if the enantiomers have basically equivalent physical properties?
The trick is to react the racemic mixture with another chiral compound to make two different diastereomers. Think about it, let's say a racemix mixture is 50/50 the + and the - enantiomers. Well, if you react them with a + molecule, there will be two results, a molecule with both chiral centers + (+,+) and a molecule with one chiral center - and the other + (+,-). Diastereomers have different physical properties, and so from here you can separate the molecules using common lab techniques like crystallization, filtration, distillation, etc. Once you have both the diastereomers isolated, you take the diastereomer that has the enantiomer you want in it and run the original reaction backwards to regenerate the enantiomer you want. The separation of enantiomers, such as those in the racemic mixture of albuterol, requires the addition of a resolving agent (a chiral molecule). When a resolving agent is added to a racemic mixture, it reacts with each enantiomer, forming a covalent bond or an ionic salt. Because the resolving agent is chiral, it incorporates a new chiral center into each enantiomer, creating a pair of diastereomers. Diastereomers can be separated from each other because, unlike enantiomers, they have different physical properties. Once the diastereomers are separated, the resolving agent is removed, yielding the original molecules as single enantiomers.
What is the electromotive force and what do pos and neg values mean in terms of spontaneous
The voltage or electrical potential difference of a cell. Positive emf means delta G is less than 0 and negative emf means delta G is greater than 0.
What determines the buoyant force an object feels?
The volume and density of the liquid that has been displaced. That's it. The buoyant force has nothing to do with the object being placed in the fluid. A bowling ball and a styrofoam ball with the same volume as the bowling ball will experience the same buoyant force despite having different masses.
Explain how something like work is a process function
The work done by or on a system is defined by the path the work took. Work can be calculated using W = F*d*costheta where F is force and d is distance. Therefore, differing path lengths (d) are built into the equation and must be considered. For further elaboration, consider the following. Two weights are at a height of 10 meters. The first weight was brought from 0 meters to a height of 10 meters, which took some amount of work. The second weight, on the other hand, went up 10 m, left 5 meters, and then right 5 meters. Both weights are in the same final position, 10 meters above ground level, but the second case took more work.
What is the work energy theorem?
The work energy theorem says that the total change in energy (work) of an object can be calculated by determining the change in an object's kinetic energy. Work also equals negative change in potential energy for conservative forces
What is theoretical yield?
Theoretical yield is the maximum amount of product that can be generated according to the balanced equation. This number is the yield associated with 100% of the limiting reactant reacting, absolutely no side reactions of any kind occuring, and no accidental loss of product during collection.
Whats important to remember about the ideal gas constant, R
There are many different forms, the relevant one will be provided in the question. Make sure everything you plug in works out with the units of R!!!
What does it mean to be isothermal and how does that affect the first law of thermodynamics equation?
There is no change in temperature (and therefore no change in internal energy) Q=W heat added to system=work done by system
What are the general characteristics of metals?
They are usually lustrous solid with high melting points. Metals also have the ability to be deformed without breaking (malleability and ductility). Finally, metals are usually good conductors of heat and electricity.
Why is overcharging Ni-Cd batteries not damaging
They will stop accepting electrons because Cd(OH)2 runs out
Describe Thin Layer and Paper Chromatography
Thin Layer and Paper chromatography differ only in the stationary phase. In TLC, the stationary phase is silica gel or alumina. In Paper chromatography, the stationary phase is paper, which is composed of cellulose. In these methods, we take our mixed product and place it on the silica or paper plate. This is called spotting, because you just make a little spot. The plate is then treated with a solvent of some sort. The solvent is the mobile phase. Generally speaking, the plates are stood upright, and capillary action pulls the solvent up the plate. The mobile phase will pull the various molecules in the spot up the plate at different rates, and as long as the rates are different enough, the samples will separate. Generally, a nonpolar or slighlty polar organic solvent is used. Since silica is polar and hydrophilic, we expect polar compounds to move less and non polar compounds to elute up the sheet more
characteristics of covalently bound compounds
This is usually how nonmetals bind other nonmetals because both of the nonmetals in the bond want to gain electrons. Dont form crystal lattices, compounds consist of individually bonded molecules
What is threshold frequency (fT)?
Threshold frequency is the minimum frequency (and therefore energy) of light required to knock electrons off of a given metal atom. Different metals will have different threshold frequencies. if it doesnt hit threshold no electrons will leave.
Which variable links the horizontal and vertical aspects of projectile motion?
Time. Once the ball hits the ground, the motion stops, both horizontal and vertical. Therefore, time is the one variable that you can solve for in one dimension and then use in another. This fact will often provide the necessary variables for solving certain kinematics problems.
What is titration?
Titration is a procedure used to determine the concentration of a known reactant in solution.
What is Newton's Third Law?
To every action(force), there is always an opposed but equal reaction.
How does one assign directionality to torques?
Torque that generates clockwise rotation is negative. Torque that generates counterclockwise rotation is positive.
What is a tosylate?
Tosylates contain the functional group -SO3C6H4CH3. Tosylates are good leaving groups. Tosylates are prepared by reacting alcohols with p-tolouenesulfonyl chloride. Derived from toluenesulfonic acid
Determining electrons per shell from an electron config
Total everything from each energy level. so if something has 4f14, it would also have 10 in 4d, 6 in 4p, and 2 in 4s, making 32 electrons in the 4th energy level. howeverm in order to have 4s14 it must fill 6s2 first, so it would only have two valence electrons in 6s
What are the tenets of Transition State Theory?
Transition State Theory states that when molecules collide with energy equal to or greater than the activation energy, they form a transition state in which the old bonds are weakened and the new bonds begin to form. The transition state then falls apart into the products.
Activated complex vs. intermediate
Transition states (activated complex) are theoretical constructs that exist at the point of maximum energy Intermediates actually exist with finite lifetimes
What is transmittance?
Transmittance is like the opposite of absorbance. If you absorb all the light, you transmitted none of it. If you absorb none of the light, you transmitted all of it. So it is the amount of light that passes through and hits the detector This means that the bottom of the valleys on the IR spectra are where the most absorption is happening.
How are alcohols commonly modified to make them better leaving groups?
Treatment with acid to protonate the alcohol makes it a better leaving group. Conversion of the alcohol to a Mesylate or a Tosylate make it a better leaving group.
What kind of molecular orbitals go into triple bonds?
Triple bonds are made of 1 sigma bond with 2 pi bonds surrounding it. The 2 pi bonds will be perpendicular to one another.
Definition of electron density in regards to resonance
True electron density is a hybrid of all resonance structures, forming the resonance hybrid Each "resonance structure" however, is describing one possible arrangement of electrons (that doesnt actually exist)
Fundamentally, how is UV-vis spectroscopy useful?
UV-vis is useful for identifying compounds with interesting electronic properties, which is basically just double bonds, triple bonds, and lone pairs that create conjugated systems.
Describe Ultraviolet-Visible Spectroscopy?
UV-vis spectra are obtained by passing utraviolet and visible light through a sample in an inert non-absorbing solvent. The absorbance of the light at various wavelengths is recorded. UV-vis light is used to promote electrons to higher orbitals, and so based on the absorbance of certain types of UV-vis light, one can glean information about the molecules electronic structure. The most important info we get from this is the wavelength of maximum absorbance, which tells us about the extent of conjugation. The more conjugated the compound, the lower the energy of the transition and the greater wavelength of maximum absorbance
What is ubiquinone?
Ubiquinone is a biologically important quinone. It is known as Coenzyme Q and it is a vital electron carrier in associated with complexes I, II, and III of the electron transport chain. In the body, it switches back and forth from its oxidized version Ubiquinone to its reduced version Ubiquinol Long alkyl chain allows it to be lipid soluble
How does Ultrasound technology work?
Ultrasound machines make ultrasonic sound waves and apply them to the surface of the patient's body. When the sound waves travel through the body, they encounter various tissues. Whenever a sound wave passes into a new tissue, some of the wave passes through the tissue and some is reflected back to the source. Different tissues allow different amounts of wave to reflect back to the source. The more the tissue reflects back to the source, the more brightly the tissue will appear on ultrasound. Using all of this, one can visualize a 2D slice of the body. One makes note of where bright/dark areas are to determine which tissues are present and where they are present within that 2D slice. You can even target specific slices of the body by manipulating the distance at which the ultrasound is operating. Distance can be calculated because you know the speed of the wave (given) and you know how long you let the wave travel (given) so you can always calculate the distance of the tissue from which the wave is reflecting. ULTRA SOUND USES TRAVEL TIME OF THE REFLECTED SOUND TO CALCULATE DISTANCE (it doesnt use intensity to calc distance) Ultrasound relies fundamentally on the proclivity of waves to reflect when they hit borders between different media.
How can ultrasound treat disease
Ultrasound waves create friction and heat when acting on tissues, which can increase blood flow to damaged tissue. Focused ultrasound uses constructive interference to creates high energy point (massive amplitude) that can break up tumors/ kidney stones/ cataracts and also be used in dental cleaning.
What is a substance's standard state?
Under standard conditions (25 C, 1 atm pressure, 1 M concentration) the state (gas, solid, or liquid) a substance takes is its standard state. FOr example, oxygen, at standard conditions, is a gaseous, neutral, diatomic compound. Iron, at standard conditions, is a solid, neutral, monoatomic compound.
Point charges undergo ________ when in a uniform magnetic field
Uniform circular motion
Where are nonmetals found on the periodic table?
Upper right side.
What is doppler ultrasound
Used to determine blood flow within the body by detecting the frequency shift that is associated with the movement toward or away from the reciever
What is X-Ray diffraction
Uses the bending of light rays to create a model of molecules. Often combine with protein crystallography. Dark and light fringes dont take on a linear appearence bit rather a complex 2D image
Generally speaking, which layer will be on top and which layer will be on the bottom in a separatory funnel?
Usually the top layer in a separatory funnel will be the organic layer, but ultimately which layer sinks and which one floats is determined by their relative densities.
How to calculate true voltage supplied to a circuit by a cell
V=Ecell-irint E is the emf of the cell, i us the current through the cell, r is the internal resistance. If the cell isnt driving any current (aka a switch is open), the internal resistence will be 0 so voltage will be equal to emf
What is VSEPR Theory?
VSEPR Theory is a system by which we can predict the shape of a molecule based on the arrangement of bonding and non bonding electrons as seen in its lewis structure.
What is a vacuum distillation?
Vacuum distillation is just like simple distillation, except a vacuum adapter is used and hooked up to a vacuum that lowers the atmospheric pressure inside the distillation apparatus. By lowing the atmospheric pressure, one lowers the boiling points of all liquids present in the distilling flask. This method is used on compounds with higher than 150 C boiling points to lower their boiling points. Heating a reaction mixture past 150 C is not a good idea, because it will put so much heat energy into the solution that it will probably cause it to start undergoing undesired reactions.
What is Vacuum filtration?
Vacuum filtration is when the liquid and solid are put under vacuum to suck them through the filter. This is the preferred method when you are more concerned with pure residue, because even though the vacuum might accidentally pull some residue through, it will also definitely pull all of the filtrate through, leaving a pure residue at the top.
What is a valence electron?
Valence electrons are the electrons that are held in the farthest energy shell from the nucleus. Because they are so far from the nucleus, these electrons are weakly held and are the most likely to be involved with interactions with other elements/the environment.
For a single lens or mirror, describe the orientation of real and virtual images
Virtual is always upright Real is inverted
What kinds of compounds can Gas Chromatography analyze?
Volatile compounds, which are low melting point, sublimable solids or vaporizable liquids.
Should you place a voltmeter in parallel or series?
Voltage is equivalent across parallel elements and split between series elements. Therefore, one should wire a voltmeter in parallel with the two points between which one wants to measure the voltage. If you place the voltmeter in series with the two points, the voltage will be split and the voltmeter will read lower than the actual voltage.
What is voltage?
Voltage is the difference in the electric potential between two points. Path independent
What are the units of potential?
Volts (V = J/C)
Volume=[...]=Loudness
Volume=Sound level (Db)=Loudness
[...]=Sound level (Db)=Loudness
Volume=Sound level (Db)=Loudness
What happens when an object breaks the speed of sound
Wave fronts build on one another at the frount of the object, creating a much larger amplitude at that point (smaller wavelength in front, longer behind). This creates a large pressure differential. This highly condensed wave is called a shock wave. The passing of a shock wave creates very high pressure, followed by very low pressure, which is a sonic boom. Note: a sonic boom can be heard any time an obect traveling at or beyond the speed of sound passes a detector, not just when sound is exceeded. https://www.youtube.com/watch?v=1pf-Is2S1_Q
What is wave number?
Wave number is an analog of frequency that is used to describe the energy level of light in IR spectroscopy. Wave number is equal to 1/wavelength. The higher the wavenumber, the higher the frequency, and the higher the energy.
What is a wavelength?
Wavelength is the distance from one feature of the wave to the next instance of that feature. For example, if one is measuring the wavelength using a crest, then the wavelength would be the distance between the first crest and the second crest.
How do we name carbons relative to the carbonyl group?
We could just call any specific carbon out on the chain using its number, but we can also call out carbons as they relate to the carbonyl group. Alpha carbons are carbons that are adjacent to the carbonyl carbon. Beta carbons are carbons that are two away from the carbonyl carbon. Gamma carbons are three away. Delta carbons are 4.
When do we use fractional distillation?
We use fractional distillation when we are trying to distill a liquid that has a boiling point less than 25 degrees C different than another. For example, we would use fractional distillation to separate two liquids with boiling points of 100 and 115, but not on two liquids with boiling points of 100 and 145.
How does one create a lewis structure for an atom/molecule?
We will use the example of HCN to illustrate the steps of lewis dot structure construction. 1. Draw out the backbone of the compound, that is, the arrangement of the atoms. In general, the least electronegative atom will be the central atom, and Hydrogen and Halogens almost always occupy a terminal position. For now, just make single bonds between them. 2. Add the valence electrons of each individual atom in order to determine how many valence electrons you have total to use. 3. Place the electrons in the lewis structure, trying to do the best job you can of making sure everyone is in an octet and everyone has a formal charge of 0. 4. Sometimes it will be impossible to get every atom to an octet with the number of valence electrons in the compound. In this case, try to replace single bonds with double bonds/triple bonds strategically. The use of double and triple bonds will almost always allow you to get every atom to an octet.
Weak acids and bases have [strong, weak, or negligible?] conjugates?
Weak acids and bases have weak conjugates?
What is strong nuclear force
What attracts protons and neutrons. Compensates for repulsive forces of protons. Strongest of 4 fundamental forces but only works at extremely small distances
How does increasing and decreasing [A] affect rate=(k1[C][A]2)/(k2+k3[A])
When [A] is high, k3[A]>>k2, so the reaction will appear first order (with respect to A) When [A] lowers, k2>>k3[A], so the reaction will appear second order (with respect to A)
Dielectrics in isolated capacitors
When a dielectric is placed in a capacitor thats disconnected from any circuit, the voltage across the capacitor decreases. This decreased voltage causes increased capacitance. Charge is constant
What is forcced oscillation
When a periodically varying force is applied to a system, the system will then be driven at a frequency equal to the frequency of the force. If the frequency of the applied force is Very close/equal to that of the natural frequency of the systme, the amplitude of the oscillation becomes much larger. will increase infinitely if no other constraints
What are kinetic and thermodynamic enolates?
When an enol forms, it can form across the alpha carbons across either side of the molecule. So, if the one of the carbons is more substituted, it will form a more substituted double bond, which is more stable. This is the thermodynamic enolate. If the unsubstituted carbon gets the double bond, the prdouct is less stable. This is the kinetic enolate. Kinetic enolates are favored by rapid, irreversible, low temperature reactions (with large strong bases) Thermodynamic enolates are favored by slow, reversible, high temperature reactions. (with small weaker bases)
What is the zeroth law of thermodynamics?
When an object x is in thermal equilibrium with an object y, and that object y is in thermal equilibirum with another object z, x will be in thermal equilibrium with z.
What is gamma decay?
When an unstable nucleus emits a gamma ray AKA a high energy photon. Gamma rays are massless and chargeless, they just carry energy and their emission helps to stabilize a high energy nucleus. They do not affect the atomic number or mass number of a nucleus.
When will an object sink or float in a fluid?
When its density is higher or lower than the fluid, respectively.
Explain the photoelectric effect
When light of sufficiently high energy strikes a metal it knocks the electrons off the metal and thereby produces a current. More intense light means more photons per unit time hit the electrode and thus more electrons are knocked off per unit time. This leads to greater current. Current is Directly proportional to the intensity and amplitude of the light beam when we are above threshold. when we are below, no current is produced. Kinetic energy of electrons DOES NOT relate to intensity, but rather to frequency of the light
How do reactions respond to changes in pressure and volume, as described by Le Chatelier's principle? Note, these changes are only seen in gas systems.
When pressure is added to a gas system in equilibrium, the reaction will push the reaction to the side of the reaction with less moles of gas, and therefore less pressure. The opposite is true. When a system contracts and the volume goes down, the pressure goes up, and again, the reaction will push the reaction to the side of the reaction with less moles of gas, and therefore less pressure. The opposite is true.
How can acid/base chemistry affect Extraction
When something is deprotonated it is more soluble in the aqeuous phase. Thus, adding a base can help extract an acid in the aqeuous phase!
When does light undergo total internal reflection?
When the angle of incident light exceeds the critical angle. If it is less than critical angle a light beam will emerge
Is an amine/-OR group electron donating or withdrawing
When the atome of nitrogen/oxygen participates through its free electron pair in resonance, the amine/methoxy group plays the role of a donating group by conjugation. When it cannot participate in conjugation through resonance, the amine/methoxy groupe plays the role of inductive electron-withdrawer group, due to the higher electronegativity of nitrogen atom compared to carbon atom. When the amine group plays the role of electron donating group through conjugation, its inductive withdrawing effect (still existing) is weaker and masked by the first effect.
What is happening when an atom is demoted to ground state.
When the electron spontaneously falls from a higher energy level to a lower energy level (THIS WILL ALWAYS HAPPEN) the atom loses some energy. This energy is lost in the form of a photon which the atom basically spits out.
What does it mean for a system to be resonating
When the frequency of the periodic force is equal to a natural resonant frequency of the system. amplitude of oscialltion at maximum This is why voices shatter glass
When does light refract away from the normal?
When the light passes from a higher index of refraction to a lower index of refraction. NOTE: Air has a lower index of refraction than water.
When the magnification is negative, the image is [...]
When the magnification is negative, the image is inverted
When the magnification is positive, the image is [...]
When the magnification is positive, the image is upright
In acid base titration, when is the equivalence point reached?
When the number of equivalents of acid and base are equal. Does NOT always have to be pH=7 (it is for strong acid and base)
How do waves behave when fixed at one end?
When there is a boundary of some sort on one side of the wave, the wave will hit the boundary and then reflect its direction and invert its orientation.
What is the Doppler effect?
When two objects are moving in relation to one another, the frequencies of the sounds they make will be altered. When the source and detector are moving toward eachother, the perceived frequency is greater When the source and the detector are moving away from eachother, the percieved frequency is less than the actual frequency
What is beat frequency and equation
When two sounds of slightly different frequencies are produced in proximity, volume will naturally fluctuate due to interference effects. These variations are called "beats" and the beat frequency can be obtained by subtracting the two freuencies that are close in pitch. The beat frequency is the frequency of the periodic increase in volume.
When waves are 180 degrees out of phase (completely out of phase) they will always [...]
When waves are 180 degrees out of phase (completely out of phase) they will always destructively interfere
When do we use vacuum distillation?
When we are trying to distill a liquid with over a 150 C boiling point. The whole point of vacuum distillation is to decrease the pressure in the system, which lowers the boiling point of the liquid so we don't have to worry about degrading the product with that much heat.
How do reactions respond to changes in concentration, as described by Le Chatelier's principle?
When you increase the concentration of something at equilibrium, the equilibrium will oppose this change by pushing the reaction to the other side of the equation. When you decrease the concentration of something at equilibrium, the equilibrium will oppose this change by running the reaction to the same side of the equation so it can replace what was lost.
Describe Ohm's Law.
Whenever you pass through a resistor, you lose energy in the form of a drop in electric potential. Ohm's law calculates the amount of potential you lose when you pass through a resistor. Note: You dont lose current, no charge is gained or lost upon moving through a resister. Current for a circuit is constant
How does one calculate capacitance due to physical properties of the capacitor?
Where A is the cross sectional area of the capacitor plates and d is the distance between them. E is 8.85E-12 F/m
How does one calculate the speed of sound in a given medium?
Where B is the bulk modulus of the medium (increases from gas to liquid to solid, so sound travels FASTEST IN A SOLID!!!!) and rho is the density of the medium.
Capacitors store energy by separating charges and creating an electric field in which to store energy. How does one calculate the amount of electrical potential energy in a capacitor?
Where C is the capacitance of the capacitor and V is the potential across the capacitor.
What is the Planck Relation?
Where E is equal to the energy in Joules. f is equal to the frequency in Hz and h is the Planck's constant.
What is the equation for the Nernst Equation?
Where Eocell is the emf under standard conditions, R is the ideal gas constant, T is temperature, n is the number of moles of electrons, F is the faraday constant, and Q is the reaction quotient. If the temperature is at 298 K (Standard conditions) the following simplified version of the equation can be used. For Q remember not to include solids. So for: Zn (s) + Cu2+ (aq) -> Zn2+ (aq) + Cu (s), Q would just be zinc ion over copper ion .
How does one calculate the amount of work done on an object?
Where F is the force, d is the distance over which the force was applied, and theta is the angle between the force and the displacement vector
How does one relate mass and weight?
Where Fg is the force of weight (gravity), m is mass, and g is acceleration due to gravity.
How does one calculate sound level?
Where I is the intensity of the sound wave and Io is the threshold of hearing 1*10-12 W/m2
How do you calculate the change in volume and molarity during a dilution?
Where Mi is the initial Molarity, Vi is the initial volume, Mf is the final molarity, after dilution, and Vf is the final volume, after dilution.
What is the equation for calculating the absolute(hydrostatic) pressure on an object?
Where Po is the ambient pressure on the liquid (usually atmospheric pressure but not always) and pgz is the pressure due to being submerged in the liquid. z indicates the depth at which the object is submerged. Rho is density of fluid
What is the equation for Poiseuille's Law?
Where Q is the flow rate, r is the radius of the space or pipe, Delta P is the pressure gradient, eta is the viscosity of the fluid, and L is the length of the pipe. The important things to notice here are the ways changes in variables affect flow rate. Increasing radius increase the flow rate a lot. Increasing length decreases the flow rate a little. Slight change in radius has huge effect on pressure gradient assuming constant flow rate
How do you calculate the Delta G of a reaction at non standard conditions?
Where Q is the reaction quotient of the reaction, T is the temperature of the reaction, and R is the ideal gas constant.
How does one calculate the energy required to promote an electron from one energy level to another?
Where RH is 2.18E-18, ni is the initial energy level and nf is the final energy level. Or they could give you R as 1.09E7 in which case the Eq would be
What are the formulas for voltage?
Where Vb is the potential at point b, Va is the potential at point a, Wab is the work required to move a charge from point a to point b, and q is the charge of the moved particle.
What is the equation for the delta G of an electrochemical cell?
Where delta G prime is the standard gibbs free energy, n is the number of moles of electrons exchanging between the anode and the cathode, F is the Faraday constant, and Ecell is the standard electrode potential. Since F is in coulombs (J/V), delta G must be in joules
How does one calculate the Doppler effect?
Where f' is the perceived frequency, f is the original frequency, v is the speed of sound, vd is the speed of the detector, and vs is the speed of the source. Use upper signs when the detector or source is moving toward the other object, and the bottom signs when the detector or source is moving away from the other object Ex. you are driving and an ambulance is approaching your rear. EVEN THOUGH ambulance is getting closer, YOU are still driving AWAY from the ambulance, so use bottom sign in numerator (negative). the ambulance is driving TOWARD you, so the top sign is used in the demoniator (negative) MNEMONIC Use the TOP sign when the detector/source is moving TOWARDS the other object.. Use the bottom sign when it is going away.
How do you relate the standard potential of a reaction to its equilibrium?
Where n is the number of moles of electrons exchanging in the reaction. F is the Faraday Constant, R is the ideal gas constant, T is the temperature, and Keq is the equilibrium constant of the reaction. If Keq is greater than 1, Ecell will be positive, meaning delta G will be negative and thus the reaction is spontaneous. If Keq=1, Ecell is 0.
How do you calculate osmotic pressure?
Where pi is osmotic pressure, i is the number of ions into which the solute dissolves, M is the molarity, R is the ideal gas constant (.0821atm-L/mol-k), and T is the temperature.
How does one calculate a fluid's critical speed?
Where v is the critical speed. Eta is the viscosity. p is the density. D is the diameter of the tube. NR is a constant known as Reynold's number which changes based on the size and shape of objects within the fluid.
Where should one assign the zero point when calculating gravitational potential energy?
Wherever is most convenient. We can pick a zero point wherever we want. Try to pick a zero point that eliminates variables.
How do we experimentally determine the rate constant and the orders of a reaction?
With experimentally determined data! This will almost always be given to you in the form of a chart.
Within a closed system flow rate is [...] at all points in the tube.
Within a closed system flow rate is equivalent at all points in the tube.
What is the difference between work function and ionization energy?
Work Function is the energy required to knock an electron off the surface of a metal, where as ionization energy is the energy to remove a bound electron from a gaseous atom/molecule.
What is work?
Work is the mechanical transfer of energy from one object to another. Change in energy (can be potential or kinetic, think charge problem from class)
How do we write relevant half reactions ***
Write the complete ionic equation and then pick the compounds that are oxidized or reduced H2+F2->2HF H2->2H++2e- F2+2e-->2F- ****incomplete*****
Can temperature alter Emf in electrochemical cells?
YES
Is electrostatic force a vector?
Yes
Is the electric field a vector?
Yes
Do diastereomers rotate plane polarized light?
Yes, but they rotate plane polarized light in weird ways. It's not like with enantiomers how its the same amount just in opposite different directions. For this reason, the optical activity of diastereomers is not as useful to analyze.
What kinds of reducing agents are needed to reduce carboxylic acids?
You need a strong reducing agent like LiAlH4. Weaker agents like NaBH4 are not strong enough to reduce carboxylic acids. (results in no reaction)
How do you pick a good indicator?
You pick a good indicator by making sure the color change (which happens at the pKa of the indicator) is close to the pH you want the indicator to change at (equivalence point).
How do we convert a second order reaction graph into a line graph?
You plot 1/concentration versus time. The slope of the line will be equal to the rate constant.
How to compare effective nuclear charge of two atoms ***
Zeff=atomic number-core electrons Cl: 17-10=7 K+: 19-10=9 doesnt work when comparing cl vs cl-, just know adding electron reduces effective nuclear charge
Format of a cell diagram
Zn (s) | Zn2+ (1M) || Cu2+ (1M) | Cu (s) 1. The reactants and products are always listed from left to right in this form: Anode | Anode solution || Cathode solution | Cathode 2. A single vertical line indicates a phase boundary 3. A double vertical line indicates the presence of a salt bridge or some other type of barrier
Concentration of radioactive substance at time t equation
[A]t=[A]0e-kt
What is a condensation reaction
a chemical reaction in which two molecules or moieties (functional groups) combine to form a larger molecule, together with the loss of a small molecule. [1] Possible small molecules lost are water, hydrogen chloride, methanol, or acetic acid, but most commonly in a biological reaction it is water.
What is the equation to calculate the centripital force and centripital acceleration on an object?
ac=v2/r
What are the most important IR spectra absorptions to know?
alone O-H bonds, broad peak around 3300cm-1 alcohol on carboxylic acids, broad peak around 3000 N-H bonds, sharp peak around 3300cm-1 C=O bonds, sharp peak around 1750cm-1 Aka carboxylic acid will have sharp 1750 and broad 3000 C-H is sharp at 3000 Alkenes 1645, less for aromatic/ conjugation alkynes 2200 3650–3200 cm−1 (O–H stretch), 3550–3060 cm−1 (amide N–H stretch), 3300 cm−1 (sp C–H stretch), 3100 cm−1 (sp2 C–H stretch), narrow and weak 3000 cm−1 (sp3 C–H stretch), STRONG 1600–1475 cm−1 (C=C stretch), 1810–1650 cm−1 (C=O stretch).
work in a closed loop process
area inside the loop
square root of 3.6E-5
change to 36E-6 so answer is 6E-3 adjust so exponent is even so we can divide by 2
What does collision theory also apply to
concentration of catalyst!
P*V on an isothermal graph is _____
constant at any point along the graph
What are traveling waves
continuously shifting points of max/ min displacement
Acid base reactions form what type of covalent bonds
coordinate covalent
How are metals linked with uncharged covalently linked non metals?
coordinate covalent bonds
Right hand rule charges
current can be direction of particle motion
Cyclohexanol vs hexanol acidity
cyclohexanol is slightly worse because the ring is slightly electron donating to the OH
Positive charges will spontaneously move in the direction that _____ their electric potential whereas negative charges will spontaneously move in the direction that _____ their electric potential. In both cases ___________ is decreasing
decrease, increase, electric potential energy Use electric potential eq and just plug in and it makes sense Note: positives will have negative voltage and negatives will have positive voltage (from equation delta V= Vb-Va) Note: Work will be negative in both cases, meaning decrease in potential energy
downfield vs upfield NMR
downfield is higher chemical shift aka more to the left. (more deshielding) Upfield is less shift from more shielding so right (towards 0)
alternate symbol for beta decay
e- or e+ Note the e- has to be a product to be beta decay, if it is on the reactant side we are looking at electron capture
What is Ecell
electromotive force
What kinds of groups increase the strength of a nucleophile/ electrophile
electron donating groups for nuc , electron withdrawing groups for elec
Melting and evaporating are ______ while condensing and freezing are______
endothermic, exothermic
What is an ideal solution
enthalpy of dissociation is 0 (heat neither required or released during solvation)
As number of microstates available to a system increases, _______ increases
entropy
When multiple gases are at equilirium, their kinetic energies are _____ but the smaller molecules have higher ______
equal, velocities
Law of mass action
equilibrium constant expression
what is acetylene
ethyne
How does one calculate the wavelength/ frequency of the standing wave in a closed pipe?
f= (nv)/4L Where L is the length of the pipe and n is limited to odd integers above zero (1,3,5... etc.). n represents the number of quarter wavelengths. limited to odd harmonics
What is the equation for the wavelength and frequency of a standing wave on a fixed string?
f=(nv)/2L where v is velocity (speed of sound for sound waves) Where L is the length of the string and n is a non-zero positive integer known as the harmonic (corresponds to the number of half wavelengths on the string).
How does one use the right hand rule?
for C = A x B 1. Point thumb in the direction of vector A 2. Point fingers in the direction of vector B 3. The direction your palm is facing is the direction of vector C
wavenumber is directly proportional to _____ and inversly proportional to _____
frequency, wavelength
Gauge pressure for fluids stacked
gauge for top fluid would just be pressure inside minus atm gauge for bottom fluid would be pressure inside minus atm minus gauge pressure of top fluid
All amino acids are L isomers and optically active except
glycine, achiral
What can you change n to in ideal gas equation, and what problems will this solve
grams/molar mass density and molar mass problems, for density just rearrange to grams/ volume and molar mass just solve for molar mass
How does a complex ion influence solubility of the ions required for its formation
greatly increases it, it can make AgCl completely soluble (when it is usually insoluble) This is because it sucks up the Ag right as it's produced shifting the EQ to the right making more Ag
heat of fusion vs heat of vaporization
heat of fusion is freezing or melting heat of vaporization is condensation or evaopration
How to name with both double and triple bond?
hex-2-en-4-yne double and triple have equal priority so just go for lowest numbers
Solubility (Ksp) of a solid in liquid _____ with increasing temp, solubility of a gas in liquid _____ with increasing temp, solubility of a gas in liquid ______ with increasing pressure
increases, decreases, increases
As equivalent resistence decreases, current _______. Thus adding resistors in parallel will ____ the current in the curcuit. When current increases, the amount of time for X amount of charge to exit the power will _____
increases, increase, decrease
electric potential energy of ionic compounds increases with
increasing atomic radii (the farther apart they are, the more distance they can travel to get to each other. Think aboit a pos and neg charge far about vs connected. the far apart ones would have more potential energy) Thus NaCl has more electric potential energy than LiF
In a parallel resistor configuration, Current will be highest on paths with the _____ resistence
least. Current is inversly proportional to resistence
Approximate pKa of strong and weak acids
less than -2 means strong and between -2 and 20 are weak organic acids
diamagnetic material
materials with only paired ectrons will be repelled from magnetic fields (Cannont be magnetized)
As a general rule in assigning oxidation numbers, the more electronegative element receives the _____ number in a bond
negative
How to remove an ion from the aqeous layer
neutralize its charge!
What is the specific heat of water?
or
What are common units for density?
or (A mL is equal to a cm3)
If Kw changes, what scale changes
pH scale
If you doubled the amount of weak acid and conjugate base of a buffer, what would happen to pH and buffering capacity?
pH would remain same but buffering capacity would double. Thus, adding acid or base would have an even smaller effect on pH
When conjugate base equals weak acid
pH=pKa (from henderson) and the buffer is at optimum functioning capacity
Incorporating density into ideal gas law
pV=nRT n= mass/molar mass just multiply by molar mass and then divide by volume to get p(molar mass)=(density)(RT)
What is the gaseus equivalent to concentration in regards to rate law, and will it affect zero order reactions
partial pressure, NO it will not since concetration doesn't matter
If waves aren't perfectly in phase or out of phase, they will experience _______ interference
partially constructive/ partially destructive Displacements still add (remember displacement below x axis will be negative and thus contribute to a reduced overall displacement)
What is a polar protic vs polar aprotic solvent with common examples
polar protic solvents can hydrogen bond (which is why they inhibit F from being a nucleophile) Ex. carboxylic acids, alcohols, water, ammonia/amines Polar aprotic solvents cannot hydrogen bond (which is why F is a good nucleophile) Ex. DMF, DMSO, acetone
Rates of diffusion and effusion are _____ to average speeds
proportional and equal to ******
What is the equation for the heat of transformation?
q = mL where q is heat, m is the mass of the substance, and L is the heat/g of the phase change in question.
Mixing two liquids and finding Eq temp equation
qcold=-qhot mcoldcΔtcold=mhotc(-Δt)
bomb calorimeter equation
qsystem=-qsurroundings msteelcsteelΔt + moxygencoxygenΔt=-mwatercwaterΔt
Doubling capacitor voltage will ______ energy stored
quadruple
What is the formula for calculating the magnitude of the magnetic field at the center of a circular loop of wire?
r is radius of wire multiply by N turns
How is the optics equation modified for plane mirrors
r=f=infinity so (1/o)+(1/i)=0 so i=-o
Sin(60)
rad3/2
Diffusion/effusion rate of a single molecule
rate=1/[(MW)1/2]
Describe the graph of a first order reaction?
rate=k[A]1 or rate=k[B]1 A first order reaction means the rate of the reaction is dependent on the concentration of one reactant. So, as the reaction progresses and the amount of reactants decreases, the reaction rate decreases. So the less reactant there is, the more slowly it gets used up. This manifests in the graph as a fast decline that gradually flattens out. A.K.A, an inverse exponential graph. NOTE: We cannot calculate the slope of this graph, it must be converted into a line graph.
describe sp orbitals
sp - seen in molecules with 2 areas of electron density. Results from the combination of an s and a p orbital. Leaves 2 p orbitals open. These p orbitals can interact with nearby p orbitals to form pi bonds.
Column chromatagrophy general characteristics
stationary phase is column containing silica or alumina beads (these beads are coated with specific things in each type of chromatogrpahy. For example, in ion they are coated with ions) Mobile phase is a nonpolar solvent, which travels by gravity
Where are electrons removed from first
subshell with highest principle quantum number (remove from 4s before 3d) In the event of a tie remove from highest l value (3p over 3s)
What is lorentz force
sum of electrostatic and magnetic forces acting on something
Change in internal energy (delta U) is positive when_______ and negative when______
temp increases, temp decreases
What is the only thing that changes equilibrium constant
temperature (increasing temp with exothermic means smaller keq, increasing temp with endothermic means larger keq) concentration, volume, and pressure don't change Keq **confirm this is correct
How does internal energy relate to temperature
they are proportionate, doubling one doubles the other
What is the boundary layer in turbulent flow
thin layer of fluid adjacent to the wall has laminar flow even when rest is turbulant. flow speed at wall is 0 and increases throughout layer
If ignoring non conservative forces, whate are the relative peak velocities of two vehicles with different horsepower
unlimited for both. HP is a measure of power (energy change over time) and with no friction both will continously increase kinetic energy (although at different rates, higher power will reach higher speeds faster)
What are the equations for electric field?
where Fe is the electrostatic force on the test charge, q is the charge of the test charge, Q is the charge of the source charge, and r is the distance from the source charge.
What is the formula for calculating the force on a current carrying wire placed in a magnetic field?
where I is the current, L is the length of the wire, B is the strength of the magnetic field, and theta is the angle between the magnetic field and the length of the wire.
What is the specific heat equation?
where c is the specific heat of the substance. mass in grams when using c=4.184 MNEMONIC: Q=MCAT
How does one calculate the frequency of the vibration of a string?`
where f is frequency, T is tension in the string, p is the linear density (mass per unit of length), and lambda is equal to the wavelength.
How does one calculate the magnification of an object?
where i and o are the distances to the image and the object, respectively.
What is the formula for elastic potential energy?
where k is the spring constant and x is the distance from the equilibrium position
What is snell's law for the index of refraction?
where n is the index of refraction, c is the speed of light in vacuum, and v is the speed of light in the medium in question.
What is the formula for the net torque on a dipole?
where p is the magnitude of the dipole moment, E is the magnitude of the electric field, and theta is the angle between them.
What is the formula for calculating dipole moment? vector or scalar
where q is charge of the dipole and d is the distance. This is a vector
What is the equation to calculate the force on a charged particle moving into a magnetic field?
where q is the charge, v is the velocity of the particle, and theta is the angle between the magnetic field and the velocity vector of the particle Note: a charge moving parallel or antiparallel to the field will experience no magnetic force because sin of 0 is 0
What is the equation for the heat absorbed or released due to change in temperature?
where q is the heat, m is the mass (in grams when using c=4.184), T is the temperature, and c is the specific heat of the substance.
What is the formula for Coulomb's law?
where q1 is the charge on the first particle, q2 is the charge on the second particle, r is the distance between the particles, and k is the Coulomb constant = 9*109
How does one calculate resistance?
where rho is the resistivity (ohm*m), L is the length of the resistor, and A is its cross-sectional area.
What is snell's law of refraction?
where the n's are the indices of refraction for the two media and the theta's are the angle from the normal of the two media. It is important to make sure you know exactly which angle is which and how to identify them on test day. Picture below clearly labels the angles.
What is the formula for calculating the magnetic field produced by current traveling through a wire?
where u is the magnetic susceptibility constant (4piE-7 (T*m)/A), I is the current in the wire, and r is the distance from the wire.
What is the formula for kinetic friction?
where uk is the coefficient of kinetic friction and N is the normal force.
What is the equation for the continuity equation?
where v is linear speed, A is cross sectional area of the pipe, and Q is flow rate
First step in Eq problems
write the balanced equation!! Ex. In a 1 liter container, 1 mole of nitrogen gas reacts with 3 moles of hydrogen gas to form .05 moles of NH3, what is Kc? Ignore the mole values they give in the problem, those are for concentration!! N2+3H2=2NH3
What does it mean when absolute value of magnification is greater than, less than, or equal to 1
|m|>1, image is larger than object |m|<1, image is smaller than object |m|=1, image is same size as object