MCAT - Chemistry and Physics

Bernoulli's Equation

P1 +1/2 ρv_1^2+ρgh_1= P_2+1/2 ρv_2^2+ρgh_2 P : absolute pressure of the fluid v: linear speed h: height of the fluid Increase in velocity, decrease in P (For constant h); No viscocity

Density of mixture formula

P1*V1/Vtotal + P2*V2/Votal

Ionization energy of N vs. O

The ionizaiton enegy of N is larger than O, due to the electron repulsion from oxygen's additional electron in the already half-filled 2p orbital

Destructive Interference

A wave that is flipped across the x-axis will have equal and opposite amplitudes at each poing along the wave, causing total descructive interference. One that is half phase shifted will only be partiallly canceled

Intensity

Amount of power (energy per unit time) delivered per unit area. The intensity of EM radiation increases with higher individual photon energy and higher emission rate (number of particles emitted per unit time)

Concave Mirror (Real = Left)

Converging; dI can be real or virual; df > 0; If real then same side & inverted; Larger if between r + f OR Smaller if greater than r; If virtual then opposite side & upright & smaller

Phototransduction

Conversion of light energy into neural impulses that the brain can understand Light is converted into electrical signals in the rods and cones and photoreceptor ganglion in the eye

Theoretical yield

Mols of Limiting Reagent * MM of product to be determined

Reduction potential

More positive = more spontaneous reductions; More negative = more non-spontaneous reductions; Reduction potentials don't depend on mols

Supersaturated

More than max amount of soltue in solvent; Solids becasue more soluble as T increases; Heat to dissolve more then cool; If we try to add more oslute, nucleation site; Crystalization will form

Electrical conductors vs electrical insulators

Most metals are conductors, most nonmetals are insulators; There are also thermal conductors and insualtors (H is propotional to the A*T(Change)/Distance)

L vs. D

Most oxidized at the top of Fischer. L is left and D is right. Dextrarotary isomers rotate polarized light clockwise. Levorotatory rotates polarized light counterclockwise.

Phototaxis

Movement of an organism towards or away from light

Magnificiation of Multiple Lenses

Multi-lens systems arranged in series provide a combined magnification equal to the product of all the individual lens magnifications

Washing solvent after recrystalization

Must be able to dissolve impurities to get rid of them. Must be cold to not dissolve any of product.

When using ideal gas law, what units is Volume in?

Need to convert volume to m^3 = 1000L

Where do ions in salt bridge flow?

Negative ions go to the anode. Positive ions go to the cathode. Salt bridge is only needed in galvanic cell.

Continuity Equation

Q = AV; Assume incompressibility; As cross sectional area decreasing from plaque, velocity increases, and thus pressure inside arteries decreases)

Q in relation Ksp

Q is the ion product or reaction quotient; Q<Ksp then unsaturated; Q>Ksp then saturated

Mass flow rate (Mass / Time)

Quanity of fluid that flows through a point at a given time; It is equal to Q * density (or Mass Concentration) ; Mass / Time = (Volume / T)(Mass / Volume)

Common ion effect

Solubility decreases when one of its component ions is present; Solute can precipitate if the solubility is lowered (common ion or a change in T+P)

Temperature & Solubility for Liquid

Solubility increases at T increases; With decreasing T, air can hold less water; Colder air can hold less H2O so the same relative humidity would result in less total water in the air

Van't Hoff plot

lnKa = -H/R (1/T) + S/R ; Graph is lnKa vs. 1/T ; Positive slope for exothermic reaction and negative slope for endothermic reaction ; Can determine Delta G by using the equation G = H - TS

Osmotic Presssure

n = iMRT

Exponential Decay in Nuclear Reactions

n = no*e(^-wavelength*t); e is Euler's number (Radioactive decay is proportional to the number of nuclei that remain) Kahn Academy Fomula: N(t) = No*e^-kt - t is the half life in years - solve for k

What do EWG & EDG do?

EWG - Helps stabilize the conjugate base, thus decreasing pKa of acid. EDG - Destabilize the conjudgate base, thus increasing pKa of the acid

What kind of solvent is acetone?

Polar Aprotic Solvent!

Induced Dipole

Polar molecule induces a non-polar molecule to become temporarily polar

Chromophore

Portion of molecule's structure which absorbs visible light protons, causing the molecule to have color.

Biconvex vs biconcave Lens

Biconvex = converging (f>0); biconcave = diverging (f<0)

Mechanical Advantage of Pulleys

# Vertical Ropes = Mechanical Advantage for Pulleys - MA is related to the number of load-sharing pulleys, but unrelated to the number of fixed pulleys that redirect forces. - There is no mechanical advantage for a single pully system (Load = Effort = Tension (opposite) - In multiple pully system, Load / (# ropes) = Effort = Tension. - Each of the tension forces on the ropes cancel out half of the load weight. - The effort required to lift the load weight is cut in half. - Displacement will increase by 2, but effort needed will decrease by 2, as the W is the same

Efficiency

% = W out / W in

Yield for coupling steps

(%)^# steps ; (% lost each round)*# of rounds = % Lost

Percent dissociation

(H+)/(HA) = % dissociated; If pH is given, then H+ = 10^-pH

Flow

(L/s) Measure of volume per unit time

Geiger counter

- A device that uses a gas-filled metal tube to detect radiation - Radioactive decay; noble gas that has lost an electron

Nickel-Cadmium Battery

- A type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes. - Cathode of Nickel; Anode of Cadmium - 2NiOOH + Cd + 2H2O <-> 2Ni(OH)2 + Cd(OH)2 - Oxidation: Cd + 2OH <-> Cd(OH)2 +.2e- - Reduction: NiOOH + H2O + 2e- <-> Ni(OH)2 + OH

Surfactant molecule

- Amphipathic & surround a micelle of oil. Reduce the surface tension of a liquid - Pulomary surfactatn reduces surface tension in the alveoli, allowing them to remain inflated when the lung is compressed during respiration - Reduces the H-bonds between water molecules at the surface and reduces surface tension. - Ex: Detergents (SDS) or solubilize liquids

Synthesis of Anhydrides

- Anhydrides are commonly formed when a carboxylic acid reacts with an acid chloride in the presence of a base - Heat is used to drive the reaction forward in the synthesis of anhydrides

P, T, & mols in Vacuum

- As vacuum is pulled, the pressure in the container drops, resulting in sub-atomospheric pressure. - There are fewer gas and molecules at the surface of the melted solid. - Molecules are more likely to escape. - Vapor Pressure = Atmospheric Pressure (which is at a Lower Temperature) - Compound will boil at a lower temperature

Mercury column

- Atmospheric Pressure = Gauge Pressure - Atmospheric pressure = density * g * h - Height of mercury column serves as indicator of atmospheric pressure (High height means high atmospheric pressure)

Coordination Complexes

- Central metal atom surrounded by one or more ligands (2, 4, or 6 coordinate bonds). - Stronger Lewis bases (Charged Oxygen, Additional lone Pair e-, Donates electrons, Lower electronegativity) can displace weaker Lewis bases as ligands within the complex. - Can occur in a series of steps, as each anion can replace the existing lewis base. - The nature of the ligands in a coordination sphere causes the metal's d orbitals to have different energies. The energy difference determines the wavelength of light absorbed.

Chromatic abberation

- Chromatic abberation refers to the formation of blurry images due to the effects of dispersion through a lens. - Failure of the lens to focus multicolored light onto a single point. - Chromatic dispersion in converging leses is corrected by using a diversing lens to increase the thickness of lens periphery - Only in lens, not mirror

Temperature for Condensation

- Condensation will occur at a lower temperature, as the gas molecules will have less KE and will condense into the liquid phase. - At higher temperatures, however, higher pressures are required for condensation to occur.

Eye and optics

- Convex structures of eye produce convergence of diverging light rays that reach eye - Image distance is constant (lens to fovea); while f can change; Light coming in should be focused on fovea and retina, which is 20mm from lens

Temperature affecting water vapor

- Decreasing temperature of water means water vapor is turning into a liquid at higher atitudes and thus less H2O gas at higher altitudes - Lower temperature means lower KE and thus less water as gas - There will be more liquid and less gas thus air will have less mass of H2O - At higher temperatures, water molecules are more likely to go into vapor phase so there will be more water vapor in the air

Nitrogen

- Diatomic nitrogen is inert and makes up 80% of atmosphere; stable triple bond; - - Air bubbling in water will only react with CO2 and not Nitrogen - For a purified compound, can react in pure nitrogen (so there is no O2 gas)

Solute affecting BP Solute affecting VP

- Dissolving ions will increase the bp of the solution; Solution will reach a higher temperature before boiling - Adding a non-volatile soltue will cause the solution to have a lower vp; Less molecules will escape, as the solute will take up space

Spherical abberation

- Due to the geometry of a spherical lens. Light rays near the edge refract more than predicted for an ideal lens. - All frequencies of light are affected by spherical abberations. - Spherical aberration of a converging lens is corrected by reducing the thickness of the lens periphery, as the light rays are excessively refracted at the lens periphery (& converge too close)

Sound waves vs EM waves

- EM waves are transverse (Oscillations are perpendicular to direction of propagation); - Sound waves are longitudinal/compression (Particles are in same direction as propagation and energy of wave) - All waves carry energy - Only EM waves propogate in vacuum

Vertical Circular Motion Normal Force

- FN = mg - mv^2/r (On top of loop) - FN = mg + mv^2/r (On bottom of loop) - FN = mv^2/r - mg (Inside loop)

Viscous Flow

- Flows in which the frictional effects are significant. - Where there is contact, water moves slower

Fraction submerged of floating object

- Fraction submerged = Displaced volume / Object volume = Object density / Fluid density - Fb=Fg, but density(object)<density(liquid)

Electrochemistry and Thermodynamics Equation

- G = -nFEcell - G = -RTlnKeq

Nernst Equation

- How electric potential is affected by T and concentration of reactions - E'cell = E - RT/zF lnQ - E' = E - 0.05916/z logQ - As products increase then E' decreases

Impurities in Titration

- Impurities that undergo the same oxidation-reduction behavior as the analyte cannot be distinguished from the analyte and decrease the accuracy of the measured equivalency point in a redox titration. - The oxidation will consume additional titrant and thus will cause more titrant to neutralize the solution

How do outer hair cells amplify the frequency of the basilar membrane?

- In order for the standing wave generated by the outer hair cells to amplify the resonant frequency of the basilar membrane, it will have to match it to produce constructive interference. - The fundamental frequency of the standing wave at each location along the organ of Corti should match the basilar membrane resonant frequency at that same location.

Intra vs. Intermolecular forces

- Intramolecular (stronger) = covalent and ionic - Intermolecular = H-bond, LDS, hydrophillic polar molecules, ion-dipole (surface tension, boilng point)

Viscocity

- Intrinsic property that characterizes the amount of friction resisting motion inside the fluid itself - KE in fluid flow is dissipated by viscous shear force acting between different layers of fluid flow (Pa * s) - Increase T decreases viscocity

pKa & Ka

- Ka is dissociation constant; Larger Ka = Smaller pKa = Stronger acid - pKa = -log(Ka) - Ka = 10^-pKa

Conditions for turbulent flow?

- Larger the reynolds number, the more likely turbulent flow. - Reynolds number decreases with viscocity and increases with diameter. - When velocity surpasses the critical velocity, then turbulent flow.

Density & Pressure in liquid vs gas

- Liquid: P = h*density*g - Gas P = density*R*T - Hydrostatic pressure for liquids is linear because as depth changes, the density of liquid remains constant - Gases are compressible and have densities that change according to forces applied to them (Non-linear behavior)

Biological mechanisms of enviornmental heat transfer

- Lung: Body heat transfered to inhaled air (conduction) & Warmed air exhaled into enviornment (convection). - Skin: Increased thermal conduction with vasodilation

Multistage Flash Distillation

- Method of distillation used to desalinate seawater; cold seawater is run through a series of coils in chambers that become progressively hotter - Superheated water enters at a high temperature and is passed through a series of flash chamber held at lower pressures. - As the water cools, pressure must be lowered so that the boiling point at that pressure is lower than the temperature of water. - This causes the water to boil again. - Water needs to have lower bp than impurities in order for it to enter the vapor phase.

Thin-Film Interference

- Multicolored arrays generated by the reflection events that occur within a a system composed of two layers of semitransparent media. - Interference occurs due to differences in travel path of the light. - Surface tension and other effects that distort the surface / thickness of a fluid may cause variations in color.

Shock wave therapy (Shock wave ultrasound)

- Non-imaging treatment! - Utilize high frequency waves to cause destructive, high-amplitude vibrations within target structures. - Small wavelengths of UV waves allow them to propogate body tissues w/o diffracting. - For maximum effectiveness, the frequency of the shock wave should match the resonance frequency of the target structure. - When f=fo, high-amplitude vibrations occur. - Allows user to adjust the frequency of the emitted shock wave to ensure effectiveness

Electroplating

- Non-spontaneous reduction is driving by electical current; Results in deposition of solid metal into cathode - molmetal = I*t / nF

What happens to pressure when open to atmosphere

- Opening will cause a decrease in pressure - To balance out decrease in P, the blood must experience an energy increase somewhere else - Specifically it will increase its kinetic energy and fluid speed

Redox Titrations

- Permangenate (Purple) to Manganese Cation (Clear); MnO4- + Sn2+ -> Mn2+ + Sn4+ -> See purple again, then there is no more Sn2+ to react with - Equivalence point depends on the number of electrons absorbed and donated - Multiply each side by the change in oxidation state! (M1V1*change in oxidation state)

Heat for phase transition

- Phase transition is the only process that requires a change in heat to maintain the same temperature - q = m*(heat of vap/fusion)

The Gabriel Synthesis Steps

- Phthalimide attacks the diethyl bromomalonate, generating a phthalimidomalonic ester - the phthalimidomalonic ester attacks the alkyl halide, adding an alkyl group to the ester - the product is hydrolized, creating phthalic acid (with two carboxyl groups) and converting the esters into carboxylic acids - one carboxylic acid of the resulting 1.3-dicarbonyl is removed by decarboxylation

Solvents for Sn1 vs Sn2

- Polar protic solvents (water and ethanol) tend to stabilize ions in solution (SN1). - Polar aprotic solvents (acetone) should be used for SN2. SN2 do not rely on carbocation, but on a strong nucleophile displacing the leavin group. Polar solvents tend to weaken this nucleophile so should not be used.

Density and Pressure Relationship for Gases

- Pressure = density * R * T - Density and Pressure are directly proportional - Density and Temperature are inversely proportional - Temperature and Pressure are directly proportional

Stereoselectivity

- Property of a chemical reaction in which a single reactant forms an unequal mixture of stereoisomers. - Chiral reagents are efficient stereoselective reagents - One is the major, one is the minor - If it is 50%, 50%, then NOT stereoselective (mCBPA epoxidation) - If it is 98%, 2% then stereoselective (Sharpless epoxidation with DET

Relative humidity

- Ratio of partial pressure of water vapor to the equilibirum vapor pressure of water at a given temperature - Same amount of water vapor results in higher relative humidity in cool air than warm air - Same relative humidity, cold air has less mass of water - How much water vapor is in the air compared to how much it could hold at that temperature

Coordination complex

- Reverse of common ion effect and increasing ability to dissolve - Formed through the reaction of a transition metal cation with a ligand

How does a sonar work?

- Sends pulses of sound waves, which hits a surface and then is reflected back to the surface. Allows judgement of depth by how long it takes to return. If it takes a longer time to return, then it is farther away. - To measure the speed of a glider using sonar, you can calculate the change in time between the two waves coming back. The greater change in time between the two waves leads to a greater calculated velocity.

Sounds

- Sound is caused by the vibration of molecules that travel as pressure waves through a medium (and thus can't propagate through vaccum): - Vibration/Displacement of molecules in a medium due to movement of longitudinal waves (compression sound); SPEED, FREQUENCY, AMPLITUDE

Specific rotation of chiral compound

- Specific rotation = observed rotation / concentration * length - Enantomeric excess = observed optical / specific rotation * 100

Bernoulli's Relationships

- Static/absolute pressure decreases with increasing velocity if height is constant, but increase in dynamic pressure - An increase in speed occurs simutaneously with a decrease in static pressure or PE - An increase in height, results in a decrease in pressure

Surfice active molecules

- Surfactants (surface active molecules) adsorb and break the strong cohesive water-water interactions. - The intermolecular forces between surfactant and water molecules are much lower than between two water molecules so surface tension decreases. - Strength of interaction between water and oil and oil-water interface are weaker, as they are forces created by induced polarity in nonpolar molecules. - The hydrophobic part is in the air (hydrophobic cap) and hydrophilic in the water.

Henry's Law

- The amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid - Concentration of gas = kh * Pgas - For solids and liquids, pressure does not affect solubility

Mass Flow Rate

- The amount of mass flowing through a cross section per unit time - kg/s - To find the power, Multiply Mass Flow rate by the Specific Heat Capacity by the Temperature needed. - Q = mass * c * change in T - Power = mass flow rate * c * change in T

Oxygen at High Altitudes

- The percent of oxygen is the same as at sea level (21%), however air pressure is 30% lower at high atitudes, due to the fact that the atmosphere is less dense - air molecules are further apart - There is less pressure to push the molecules together - The number of oxygen molecules per breath is reduced (fewer oxygen molecules in the same volume of air we inhale) - The volume of a mass of air is not constant

Hydrostatic Pressure

- The pressure fluid molecules in a static column of fluid exert on eachother and surroundings - Higher P to lower P - P results from the weight of the fluid above - Container shape does NOT influence hydrostatic pressure in a column of noncompressible fluid with constant density

What will happen to water level when you throw a rock off a ship?

- The water level will fall. - The water displaced at first is larger than the water displaced after. - This is because the rock will sink to the bottom, so the buyoant force will be less. - The buoyant force afterwards is less, thus there is less water displaced.

Projectile Motion

- There is no gravity in the horizontal direction. There is only gravity effecting the vertical direction. If the initial velocity is horizontal, the rocket will decend at the same rate and spend the same time in air. Sin(0) = 0 - Max height = v^2 / 2g - Total time = 2v / g

Galileo thermometer

- This thermometer is only useful for measuring temperatures around 16 to 34 degrees Celsius - As temperature of a liquid increases, volume expands, and density decreases. Bulbs with higher temperature (lower density) will sink last. Bulbs with lower temperature (higher density) sink first.

Hyperopia

- Uncorrected: Eye too short or optical power too low. Image forms behind focal plane of retina. - Corrected: Does not diverge enough, so place a converging lens. Converging lens increases optical power. Image now forms on focal plane of retina (Image shifts closer to eye's lens).

Myopia

- Uncorrected: Image forms in front of the retina as rays converge too much. - Corrected: Place a diverging lens to shift the image away from the lens.

How to calculate the amount extracted?

- Use the partition coefficient for extraction - If there are 10 g of substance, then X g will be found in the organic layer & 10-X g will be found in the aqueous layer. - If there are two rounds of extraction, (10-X) is used as the starting material for the aqueous layer.

Metal oxides

- Vast majority of metal oxides are solid at room T - Basic - They typically react with water to form bases or with acids to form salts. MO + H2O → M(OH)2 - Only soluble with group 1A metals

H-H Equation for Buffers

- Weak acid and CB; Weak base and CA - Strong acid + weak base -> Strong acid protonate base - Strong base + weak acid -> Strong base deprotonate acid - ANY TIME there is a weak acid or base, use H-H equation for BUFFER - May need to find the limiting reagent and use ICE table to find the respective concentrations

Charging a Battery

- When charging a battery, an external potential must be applied to force the oxidation-reduction reaction in the nonspontanous direction. - The reverse reaction requries more than the potential produced by the battery because of internal resistnace - Decomposition reactions are electrolytic

X-ray Diffraction

- X-rays diffract within molecules because the space between atoms is comparable to the wavelengths of x-rays. - X-rays can't undergo classic slit diffraction (wavelength too small). - X-ray diffraction through a sample of purified and crystallized material can be used to determine its 3-D molecular structure and packing. - The patterns of bright spots produced on photographic film is indicative of molecule's 3D structure.

Effective nuclear charge

- Zeff = protons - S (shielding electrons); increases across a period - The net positive charge experienced by valence electrons

Finiding volume of solution containing solute

- mol/mL: n = CV ; V = n / C ; - g/mL: You can divide m / C = V (If the concentration is in g/mL instead of mol/mL)

Parts per million vs Parts per billion

1 parts per million = 1,000 parts per billion

Poiseuille's Law

-Calculates rate of flow through a pipe of confined space (laminar flow) Q= (πr^4 ∆P)/8ηL η: viscosity of the fluid Q: flow rate (volume flowing per time) ΔP: pressure gradient r: radius of tube L: length of tube Flow rate is proportional to radisu^4

Sn1 vs Sn2 solvents

-Sn1 = polar and protic -Sn2 = non-polar and aprotic

Dielectric material

-insulator (air, glass, plastic) -introduced b/w the plates of a capacitor - increases capacitance by a factor called dielectric constant (k) - Increase capacitance; decrease electric field; decrease voltage (charge is constant)

Two rules for action-reaction pair

1) Must be the same type of force 2) Must act on different objects - The normal force is NOT an action-reaction pair

Calories to kJ (Heat Energy)

1,000 cal = 4.2kJ ; Specific heat of water = 1cal/gC

Isolating an Ionic Subststance

1. Add a salt (NaCl or KCl) to help the substance crystalize by forming an ionic solid. 2. Add a solvent that is miscible with water. Ethanol is miscible with water but still less polar. The crystals can easily precipitate

Types of radioactive decay (irreversible)

1. Alpha: alpha particle containing 2 protons & 2 neutrons are emitted 2. Beta-minus: a neutron goes to proton and electron ejected (to maintain charge) 3. Beta-plus: proton goes to neutron and positron emitted 4. Electron capture: proton to neutron and grabs electron 5. Gamma decay: ionizing radiation, emit high energy photon from excited nucleus

Nomenclature Functinal Group Priority

1. CA (carboxy or oic acid) 2. Aldehyde (oxo or one) 3. Alcohol (hydroxy or ol) 4. Amine (amino or amine)

Solubility Rules: Insoluble

1. Carbonates (CO32-), phosphates (PO43-), Sulfides (S2-), Sulfites (SO32-) EXCEPT with alkali 2. Metal oxides & hydroxides are insoluble (MnOm) except with Ca,Sr,Ba

How to find Avogadro's Number?

1. Charge per electron / Charge per mol of electrons = 6.02 * 10^23 electrons per mol. 2. Mol * number of particles = 6.02 * 10^23 electrons per mol

How to seperate enantiomers?

1. Chiral Chromatography & Resolving Agents: Chiral column chromatography with a chiral stationary phase. Use substances which interact differently with one enantiomer than the other & must introduce one or more chiral compounds. 2. Resolution by recrystalization: Chiral reagent is used to form two distanct diastereometric salts, whicha are then recrystalized seperatetly

Properties of gas

1. Compressible 2. No fixed V or shape 3. Flows easily 4. Occupies more space

Hot air vs Cold air

Hot air rises and cold air sinks, becasue cold air is more dense than hot

Extraction of Amines, CA, Phenols

1. Extraction of amines: Dilute acid (5% HCL) will protonate the functional group, forming a + charged ion. Resulting cationic salts are freely soluble and can be removed. 2. CA: Weak base (5% NaHCO3) converts acid into salt 3. Phenol: Dilute base (10% NaOH) will convert phenols into corresponding salts & also extract CA

What conditions need to be true for a doppler effect?

1. Fluid needs to be moving 2. The moving fluid/object needs to be moving at a different velocity than the sound source 3. At least some of the componenet of the fluid's velocity must exist in the same directional plane as the wave's velocity

Number of Nodes/Antinodes in Closed Tube

1. Fundamental: 1 node, 1 antinode 2. 1st Overtone: 2 nodes, 2 antinodes 3. 2nd Overtone: 3 nodes, 3 antinodes

Number of Nodes/Antinodes in Open Tube

1. Fundamental: 1 node, 2 antinodes 2. 1st Overtone: 2 nodes, 3 antinodes 3. 3rd Overtone: 4 nodes, 5 anitnodes

Configurational Isomers

1. Geometric (Cis-Trans) 2. Optical (Enantiomers)

Diol Reactions

1. How to make a diol? - OsO4 to the double bond - KmnO4 & OH- to the double bond 2. How to make an aldehyde from a diol? NaIO4, Pb(OAc)4, HIO4 (Cleaving diol to make aldehyde)

What decreases blood viscocity?

1. Hydration (Higher volume, lower contents) 2. Anemia (less RBC) 3. Blood-thining medication

Strengths of Ionic Species

1. Neutral salts formed from strong acid + strong base 2. Acidic salts formed from strong acid with weak base 3. Basic salts formed from weak acid with strong base 4. Salts formed from weak acid and weak base must be determined by calculation

Lewis Dot Structure

1. Obey octet rule 2. Molecule needs to have correct number of total valence electrons 3. Molecule needs to have the same net charge as written

Compound Microscopes

1. Objective converging lens produces an inverted real image. 2. Eyepiece converging lens produces a larger inverted virtual image (But it is erect with respect to the first image formed). If second image is dependent on the first image. If the first image is inverted, it is a real image. If the second image is inverted, it is a virtual image, as it is upright with respect to the first image.

Nucleophilicity factors

1. Solvent - increase down a group in polar protic 2. Charge - negative charge 3. Stereics - less bulky 4. en - as en increases, nucleophilicty decreases

Properties of liquids

1. Takes shape of container 2. Definite Volume 3. Does NOT expand (incompressible) 4. bp above room T 5. Flows easily

Colligative properties

1. Vapor P Reduction 2.Boiling P Elevation 3. Freezing P Reduction 3. Osmotic P Deal with molality

Solubility Rules: Soluble

1.Alkali metals are always solutble (and NH4+) 2. Nitrate (NO3-) chlorate (ClO3-), acetate (CH3CHOO-) always soluble 3. Halides usually soluble except with Ag,Pb,Hg 4. Sulfate (SO42-) usually soluble except with Ca, Sr, Ba, Pb

How to decrease solubility of saturated solution?

1.Cooling a beaker and remove X via precipitation 2.Adding additional solvent to decrease concentration X 3. Adding a salt with common ion to compound X would decrease solubility via common ion effect 4. Increasing the pressure would cause solute to precipitate out (Le chatelier principle shift to less number of mols) 5. Coordination complexes and reacting with a solute's product ions

Six phase changes

1.Melting or fusion (Solid to liquid) 2. Evaporation (liquid to gas) 3. Sublimation (solid to gas) 4. Condensation (gas to liquid) 5. Freezing (liquid to solid) 6. Deposition (gas to solid) - Heat involved is q = m*(heat of phase change) - Heat added to a phase change will NOT raise temperature as it is an isothermal process

Kinetic molecular theory

1.Small particles move quick+randomly 2. Negligible attractive forces 3.Most of V of gas is empty space 4.Ave KE is proportional to T 5.Particles are in constnat motion 6. Gaseous mixtures do not act differently from pure gases

Type of isomers

1.Structural 2. Configurational a. Stereoisomers (cis-trans) b. Optical isomers (enantiomers and diastereomers) 3. Conformational (Same compound)

Lens Maker Equation

1/f = (n-1)(1/r1-1/r2); Same side as object then R is negative; Opposite side as object (outgoing light) then R is positive; R1 is the radius that it hits first; R2 is the radius of outgoing light

Ideal simple machines

100% efficiency, meaning that input work is used to produce output work; Levers, pulleys, incline planes act to modify the magnitude or direction of applied force

Phase DIfferences

180 = Complete Destructive, 90 = Partially out of phase, 0 = Complete Constructive

Density of water

1g/mL = 1g/cm^3 = 1kg/L = 1000 kg/m^3 (Something that is half as dense will be half submerged)

DENSITY OF WATER

1g/mL = 1g/cm^3 = 1kg/L = 1000kg/m^3

Range of Human Hearing

20Hz to 20kHz, so anything greater than 20kHz is ultrasound

Ratio of Radioactive Decay Formula

2^n-1 = Ratio of Decay, where n is the number of half lives

Equation number of orbitals in E level & subshell

2l+1 for subshell; n^2 for energy level

Trigonal bipyramidal molecular geometry

5 coordinate ligands (120 and 90 degrees); Trigonal bipyramidal, see saw (1 lone pair), T-shaped (2 lone pairs), linear (3 lone pairs)

Octahedral moleculear geomtry

6 coordinated ligands (90 degrees); Octahedral, square pyramidal (1 lone pair), square planar (2 lone pairs)

Phenolphthalein pKa

9.3; When conducting strong base and weak acid titration, the end point will be at a pH greater than 7; Reversible change in protonation state of indicator so the pKa of a chosen indicator should be within +/- unit of target pH

Diagonal Polarization

A wave polarized along the x-axis totally in phase with a wave polarized along the y-axis produces a combined wave that is polarized between the x and y axes at 45 angle.

Resolving agent

A chiral molecule that can change the physical properties of enantiomers to create a pair of diastereometers. The resolving agent is removed once the diastereometers are seperated to yield the original molecules as single enantiomers. Enantiomers have the same physical and chemical properties.

Stereospecific

A given starting material produces only one product. Ex: Halogenation of alkenes is an anti-addition reaction

Ionization energy and reactivity

A higher IE makes the compound less reactive. Elements with a lower first ionization energy are easier to ionize in reactions than elements with a higher ionization energy

Strecker synthesis

A method of synthesizing amino acids that uses condensation between an aldehyde and hydrogen cyanide, followed by hydrolysis.

Molecule vs Compound

A molecule is any arrangement of two or more atoms that, as a whole, has its own properties. A compound is a type of molecule that consists of two unique elements.

Extraction prodecure

A molecule's charge or polarity may be modified to increase or decrease affinity for a solvent. DNA can be precipitated by neutralized its charge. Hydrophobic into organic layer and polar/charged into aqueous layer.

Compton scattering

A photon loses energy to an electron when it undergoes compton scattering (and increases in wavelength). The percent change in wavelength = (1-costheta)*100% ; Final wavelength = initial + change in wavelength

Mass Spectrometry analysis

A plot of ion mass abundance vs. m/z ratio is generated; fragments of the sample can be identified by the m/z difference between two peaks in the mass spectrum. For a singly charged protonated ion, one data peak would be observed with a molecular weight one unit greater than the unprotonated form

Abscissa vs. Ordinate

Abscissa is the x-axis. Ordinate is the y-axis.

IR Spectroscopy

Absoprtion of light directly into chemical bonds; specific wavelegnths depending on the bond; The stronger the bond, the higher the vibrational stretching frequency

Types of Sound Attenuation

Absorption, Refraction (Change in direction), Scattering (Non-unifrom manner)

Half life equation

Amount lost = 1-0.5^n vs. Amount remains = 0.5^n

Ketal / Acetal hydrolysis

Acidic conditions and the presence of water; Not in basic conditions as there would need to be the loss of an alkoxide leaving group

Acyl Bromide Formation & Bromination

Acyl Bromide Formation: Add PBr3 & Br2 to carboxylic acid. Bromination: Bromination adds bromine to the double bond of the enol form. Add to alpha Carbon.

Calculating Mass of Hydrated Solution

Add the molar mass of the water solution to the molar mass of the compound. Multiply the total molar mass by the number of mols of the compound.

Solute effect on bp & vp

Adding solute decreases vp -> Greater KE required for which water molecules can break through liquid surface -> More energy needed to reach external pressure -> Increases bp

Adibiatic vs. Isothermal on Graph

Adibiatic curve is steeper; The magnitude and work done for isothermal is greater

Latent Heat of Fusion

Amount of energy needed for the fusion (melting) of 1 unit of mass. (J/kg). Smaller latent heat of fusion means it will melt more.

Formula for alkane, alkene, alkyne

Alkane: CnH2n+2; Alkene: CnH2n; Alkyne: CnH2n-2

Electron Donating Groups

Alkoxide, Hydroxy, Ester, Alkyl, Amide, Amine, Alkoxy

Double-displacement reaction

All of the oxidation states do not change

Amino acid titrations

Amino acids are diprotic acids with two acidic hydrogens; For polyprotic acids, an acidic H will produce an inflection point only if it is is acidic and if the pKa differs from any other acidic hydrogen of the acid by 10^4

Ammeter vs Voltmeter

Ammeters measure current and are connected in series; Volmeter are used to meter voltage drop so wired in parallel; Both have zero resistance

Atomic light emission

An electron is excited by absoprtion of energy and releases light (emits photon) when it relaxes to original energy state

Inertia

An object's inertia is proportional to its mass and it is the tendency of an object to resist changes to its speed. Due to the brain's inertia, the brain can continue to move independent of the skull and result in a contrecoup injury.

Doppler Effect

An observed change in the frequency of a wave when the source or observer is moving f' = fo (vsound+vobserver / vsound+vsource) ; fo is source frequency ; vsound is usually 340m/s ; if source or observer is stationary then velocity is 0

Anode vs. Cathode electrolytic cell

Anode is positive (higher potential); Cathode is negative (lower potential); In SDS, DNA migrate towards the anode

Permitivity

Any form of matter has a permitivity that is higher than that of free space

Cylinder

Area = 2*pi*r^2 + 2*pi*r*h ; Volume = pi*r^2*h

Sphere

Area = 4*pi*r^2 ; Volume = 4/3*pi*r^2

Thermodynamic Reason Behind Protein Denaturation

At high temperatures, the combination of an unfavorable entropic state and high temperature causes delta G to rise and become unstable.A folded protein is a highly unfavorable entropic state, which will become even more unfavorable at high temperatures.

Atmospheric Pressure

At sea level: 1atm, 10^5 Pa, 100kPa, 750mmHg, 760Torr

Vibrational modes

Atoms within a molecule exhibit continual vibrational motion. If the vibrational motion of a bond causes a transient, unqual distribution of electron density between the atoms within the bond, an oscillating dipole will form. If a net change in dipole is produced by a particular vibrational mode, the vibration is IR active. It will absorb IR light at particular frequencies proportional to the frequency of bond vibration

Hydration or solvation

Attractive force of an ion molecule cause a thin shin of water to surround it. H+ never exists in solution alone, it usually exists with H3O+.

Calculate MRI strength

B = uoI/2r; Increase radius decreases strength; increase current and resistance increases strength

Magnetic field inside solenoid

B = uonI, where n is the number of turns per length

Decarboxylation reactant

Beta-dicarbonyl compounds undergo decarboxylation to remove CO2

Tension at Base & Apex of Cochlea

Base has higher T & lower thickness and is displaced more by higher frequency. Apex has lower tension & higher thickness and is displaced more by lower freqency.

Powering Battery reaction

Batteries convert chemical energy to electric energy to kinetic energy to thermal energy

Velocity & Pressure in Blood

Blood is non-ideal fluid, so Venturi effect does NOT apply. When blood vessel is constricted, area is decreased, velocity is increased AND pressure is increased.

Fractional Distillation

Boiling points of the compounds to be seperated are within 25 degrees celcius of each other

Nonbonding electron transition

Bonding MO (pi) -> Nonbonding MO (n)-> Antibondy MO (pi*)

Speed of Sound

Bulk Modulus is ability to resist compression; Speed is mainly influenced by compressibility of the medium; Sound travels most slowly through air (300m/s) & Fastest in solid (5000m/s); However, it travels slower in dense medium, because dense media contains more molecuels & resistance

Reducing sugars

In linear form, the anomeric C is aldehyde or ketone and in cyclic form reducing sugars have hemiacetal or hemiketal configurations

Molar solubility vs g solubility

Mol solubiltiy = mol / mL ; Gram solubility = g solute / mL solvent

Bomb cell

Closed system where heat can be exchanged, but not matter. Volume is constant. Can withstand high temperatures. Reaction takes place in the metal.

Center of Mass

CM of a system of point masses is the average of the masses weighted by their displacement from a fixed reference point: rCM = m1r1+m2r2 / m1+m2 ; CM shifts in the same direction as a redistribution of mass and fluid ; The pivot point for an unrestrained object (human) is the center of mass

Confomers

Can freely convert between forms with no bond breaking (chair and boat of cyclohexane)

Carbonate nomenclature

Carbonate: Co32-; Bicarbonate: HCO3-; Carbonic acid: H2CO3

Mass Spectrometer Forces

Centripetal Force = Lorentz Force qV = 1/2mv^2

Linear Expansion

Change in L = (Coefficient) * L(original) * Change in T ; Thermal expansion (of a length or volume of a substance) is lineraly proportional to change in temperature

Electron Affinity

Change in energy associated with adding an electron to a neutral atom in the gas state. The more negative the electron affinity, th emore readily an atom accepts the addition of an electron (nonmetals more likely)

What happens when you charge a capacitor?

Charge on the capacitor increases and the current throughout the circuit begins to decrease

Charles and Boyles law

Charles: V prop to T; Boyles: V inversely prop to P

Combustion reaction

Chemical Energy (&O2) causing temperature of gases to increase (Thermal Energy) which can cause Kinetic Energy

Digestion reaction

Chemical energy into chemical and thermal energy

Cis vs. Trans Stability

Cis isomers can rarely stack close to one another, preventing strong intermolecular interactins. By contrast, trans isomers are capable of stacking more closely and thus experience greater intermolecular interactions. Cis isomers are compact, trans isomers are linear

Litmus Paper

Coated with litmus dye that changes color depending on the pH of the solution in which it is immersed in. Acidic solution will change blue to red. Basic solution will change red to blue.

Partition Coefficient for Extraction

Coefficient = Solubility in Organic / Solubility in Aqueous; Coefficient = Concentration of Solute in Organic / Concentration of Solute in Aqueous

Circular polarization

Compounds with chiral centers are likely to induce circular polarization, becase they absorb right and left circularly polarized light to different degrees; Helical molecular structures also indcue circular polarization of light

Elastic Modulus

Compressive strength; E = Stress / Strain

Concave vs Convex Miniscus

Concave: Strong adhesion (polar), Convex: Weak adhesion (nonpolar)

What material is a resistor made of?

Conducting material. It impedes electron flow, but does not stop electron flow.

How is heat transfered?

Conduction, convection (Fluids), radiation

Conjugate base of monoprotic acid vs. diprotic acid

Conjugate base of a monoprotic acid would be -1 anion; Conjugate base of a diprotic acid would be -2

Convex Lens; Bi-convex in eye (Real = Right)

Converging; dI can be real (+) & inverted OR virtual (-) & upright; df > 0; Real image if larger than focal length (Larger if between F and r; Smaller if beyond r) OR Virtual image if smaller than focal length

Heat capacity at constant P vs V

Cp = 5/2nR Cv = 3/2nR Heat capacity of monoatomic gases only depend on number of moles Smallest moles has smallest heat capacity and will change T by greatest amount when absorbing same amount of heat

Electrospray ionization mass spectrometry (ESI-MS)

Creates ions by protonation of the analyte. The analyte is passed through an electrospray needle that has a potential differnece applied with respect to a counterelectrode. This leads to formation of charged droplets which are repelled toward the counter electrode and mass spec upon evaporation.

Conditions for Total Internal Reflection (High n to Low n)

Critical angle = arcsin(n2/n1); Sin<1 so n1 > n2; TIR occurs when angle of incidence = critical angle ; Larger angle means more likely for TIR

Why is solid less dense than liquid for water?

Crystalline strcuture; The bent structure of water maximizes H-bond that occurs in solid phase, producing structure with large empty spaces

Direction of current vs. electron flow

Current flows opposite to electron flow; Electrons flow to the positive end of the terminal; Current flows from positive to negative end

How to decrease resistance in wire?

Decrease T; increase radius; decrease length

Increase the voltage in galvanic cell?

Decrease the substance being oxidized and increase the substance being reduced. Q = oxidized / reduced & E = Ecell - 0.06 log (Q).

Percent Recovery

Decreasing the initial amount of reactant will lower amount present in solution but will NOT change percentage recovery; Changing pH by altering the buffer solution will alter recovery

Freeze-drying

Dehydration process for food calorimetry. Lyophillisation removes water from frozen food samples at low P through sublimation (Solid -> Gas). Sublimated water vapor (gas) is collected in a condensation chamber (Gas -> Liquid)

Gibbs Free Energy

Delta G = -RTlnKeq; Keq less than 1 is to the left; Keq greater than 1 is to the right; ln0.x = negative number

Eluting Strength in TLC

Depends on how strongly a compound absorbs onto the absorbent. Eluting strength increases with increasing solvent polarity. Methanol is more polar than pentane and thus has a greater eluting strength

Relative Velocity

Depends on their directions. The minimum velocity occurs when the velocities are in the same direction (Subtraction). The maximum relative velocities occur when they are in opposite directions (Addition)

Doppler Ultrasound Imaging

Detects moving of movement flow; Blood as moving sound source & observor as stationary inducer; Use doppler equation to determine how quickly blood is moving & direction

Deuterium vs. Hydrogen

Deuterium has one extra neuron and has a larger atomic mass; It has the same number of total protons as H

Nonpolar solvents

Diethyl ether, hexane, benzene, toluene, chloroform, dichloromethane

Why is HF a weak acid?

Fluorine is the most electronegative and has the smallest atomic radius of the halides, resulting in strong bond formation

Epoxide Reagents

Diol -> mCPBA -> Epoxide

Induced polarity

Dipole-dipole interactions; Permanent dipole (polar molecule) & Non-polar molecule (Induced dipole)

Rechargeable Batteries

Discharge (galvanic) & Recharge (electrolytic)

Dispersion

Dispersion refers to the phenomenon of different frequencies of light having slightly different refractive indices. Light with higher frequency has a higher index of fraction and thus refraction. As light changes medium, its wavelength changes (But frequency stays the same). n1(wavelength1) = n2(wavelength2). Index of refraction is inversely proportional to wavelength and directly proportional to the frequency of light.

Eye as a biconvex lens

Distance of image is fixed; Approximate dI = df when dO gets farther away; Nearsightnedness: dO = infinity & dI = far point; Farsightnessness: dO = 25 & dI = near point; Human eye produces a real, inverted image when object is further from focal length; Image is smaller when the object distance exceeds twice the focal length

What does a diverging lens do to optical power?

Diverging lens decreases the optical power by increasing its focal length.

Convex Mirror (Real = Left)

Diverging; dI is always virtual (-) & smaller & upright; dI opposite side; df < 0

Concave Lens (Real = Right)

Diverging; dI is always virtual (-) & smaller & upright; df < 0; dI same side

Neutralization

Do not always results in a solution of neutral pH, as the product salt may be acidic or basic; H+ and OH- cancel to make water

Metathesis Reaction

Double Displacement Reaction. Reactant ion pairs are exchanged.

Bisphosphonates

Drugs that prevent the loss of bone density. Composed of two phosphate groups

Electric field, Voltage, Electric Potential

E = kQ/r^2; V = kQ/r; U = kQ1Q2/r

Nuclear Fusion Energy

E = mc^2, where m is equal to the mass defect (Predicted mass - Actual mass)

Electrolytic cells

Electrical energy drives non-spontaneous reaction; Breakdown of water to hydrogen and oxygen gas (2H20 -> 2H2 + O2); Anode is positive and cathode is negative

Toasting bread reaction

Electrical energy is used to make thermal energy (toaster to become hot) and change the chemical composition (chemical energy is produced)

Friction and Net Force Equation

Fnet = (mgsintheta) - (usmgcostheta)

Ortho, Para, Meta

Electron donating (Lone pair of electrons) = Ortho (1,2), Para (1,4), and Activating Electron Withdrawing (No lone pairs): Meta (1,3) & Deactivating (But halogens are electron withdrawing and ortho/para)

Electron vs Molecular Geometry

Electron geometry: Number of hybrid orbitals (e- dense areas) formed around the atom; Molecular geometry: More specific adn is determined by the orientation of bonds around the electron and the nonbonding electron pairs are ignored

UV Spectroscopy

Electronic excitation from HOMO to LUMO; Relaxation generates fluoroesence

Accelerometer

Electronic sensor that measures the acceleration forces acting on an object, in order to determine the object's position in space and measure movemetn. Uses change in electric signal

Inductive Effect

Electrons are donated through sigma bonds. Electronegative atoms tend to create dipoles, partial charges, and better leaving groups, and have greater inductive effects (stabilize negative charge after being elimated)

Conditions for an air embolism

Embolism is caused when a bubble of air is formed. Gases are less soluble at higher temperatures and lower pressures.

What is fluoresence?

Emission of a lower-energy photon from a flurophore excited by the prior absorption of a higher energy photon. Molcules absorb UV light and emit lower energy wavelengths of visible light through fluroesence.

Dissolution reactions

Endothermic (require heat input) so decrease the Temperature; All dissolutions increase Pressure

What is a volt?

Energy per charge (J/C)

Latent Heat

Energy used in the process of phase change. A negative latent heat implies the phase change that is occuring is consuming energy (Endothermic and bond breaking). A positive latent heat means that phase change that is occuring is releasing energy (Exothermic and bond forming)

Thermodynamics of Protein Folding

Enthalpy is negative (Bond forming) & Entropy is negative (More ordered). Protein folding is only favorable at lower temperatures.

Configurational Entropic Penalty

Entropic penalty occurs when a small molecule binds to a protein, restricting teh movement of the protein (Loss of configurational entropy)) & binding affinity suffers a penalty. Increased conformational flexibility increases the entropic penalty of protein-ligand binding

Entropic Penalty

Entropic penalty refers to the thermodynamically disfavored requirement of forming a cage of polar solvent molecules around surface-exposed hydrophobic portions of a molecule.

Pure crystalline substance (3rd Law Thermo)

Entropy is 0 at 0K; absolute zero

Epoxidation

Equal mixture of stereoisomeric products

Ester nomenclature

Esters are named by stating the alcohol chain prefix followed by the name of the CA, with the suffic -ic replaced by -ate

Ethanol as a solvent

Ethanol is misible with water and can act as a polar&non-polar solvent.

Crack of a whip

Exceeds velocity of the speed of sound

Hooke's Law

Extension is directly proportional to force until the spring reaches it's elastic limit F=-kx ; Direction of elastic force is towards equilibirum

How does HNMR work?

External magentic field is applied to a sample in NMR spectroscopy. Radio raves, low in energy, are used to detect H-atoms adn excite from alpha spin to beta spin. Inside magnetic field, protons aligned in alpha or beta spin.

Calculate Faraday's Constant

F = (Electronic Charge)(Avogadro's Constant)

Torque

F*l*sin(90); If Force acts at the lever arm, then there will not be any torque

Buoyant Force

Fb=density*V*g; Any fluid (liquid or gas) can provide a Fb

Molar solubility

Find number of mols needed to dissolve for solution to be saturated

Bernoulli's equation for conservation of energy equations

Finding the height of a a tube filled with fluid (open to atmosphere): velocity = sq(2)(g)(h) ; 0.5*density*volume*v^2=density*volume*h ; Need to know at least ONE velocity to use equation

Color of Gases

Fire gases- such as carbon monoxide, are generally colorless Vapor and particulates- give smoke its varied colors Cl2 has a yellow-green color, NO2 has red-brown color, while CO2, H2 and NO are colorless. Cl2 and SO2 have odor, while CO2, H2, NO are odorless

Fundamental wavelength

First harmonic, two nodes Wavelength = 2L

Mass concentration

For a pure chemical, the mass concentration equals its density

Buoyant Force for Two Different Fluids

For an object fully immersed in two different fluids, the volumes of the fluids displaced are equal to the volume of the object (V1=V2=Vobject). The ratio of buyant forces is equal to the ratio of fluid densities. Buyoant force is proportional to the density of fluid.

Keq and Temperature

For exothermic reaction, increase T drives to reactants; For endothermic reaction, increase T drives to products

5 C ring with 2 double bonds

Furan (Oxygen), Pyrrole (Nitrogen), Thiophene (Sulfer)

Lorentz Force

Force exerted on a moving particle in a magnetic field: F = qvB

Analyzing Mass Spectrometry

Fragmented ions are detected. The tallest peak is the most stable peak & the highest abundance. The highest m/z ratio is the molecular ion.

Viscous friction force and Shearing Force

Fshear = n (v2-v1)/y

Strong acids

H2SO4, HCL, HBr, HI, HNO3, HClO3, HClO4 -> Ka greater than 1

Mesylates or Tosylates

Good leaving groups as they are resonance stabilized (SO3CH3)

Mechanical Potential Energy

Graviational Potential Energy or Elastric (Spring) Potential Energy

Water is amphoteric

H3O+ is strongest acid; OH- is strongest base; Kw is not 10^14 under all reaction conditions; Auto-ionization is favored at higher T; pH 7 meaning neutral ONLY at standard Temperature; Kw is so small because water is such a weak acid and base

Naming acids

HClO4 = perchloric acid; HClO3 = chloric acid; HClO2 = chlorous acid; HClO = hypochlorous acid; "ic" refers to polyatomic ion acting as an acid; "ous" means fewer oxygen than "ic"

Daniel Cells

Half reactions carry out in different container; Salt bridge contains spectator ions (Anion move in opposite direction to electron flow); Electrons flow from anode to cathode; Anode will shrink and Cathode will grow

Concentration cells

Half reactions carry out in same container; Elecrodes made of same material; Two regions must have concentration differentce; Porous disk

Electron Withdrawing Groups

Halogens, Carbonyl, Sulfonyl, Cyano, Nitro, Haloalkyl, Ammonium (Give partial positive charge, deshields hydrogens)

Photons

Have no charge, so are not affected by magnetic fields

Headlights in Car

Headlights form a concave mirror creates a parallel beam which narrowly focuses light. The light source in the headlight produces light rays in all direction (convex refelctive surfaces)

(Molar) Heat capacity vs Specific Heat capacity

Heat capacity = mc Specific heat capacity = c ; C = q/T Molar heat capacity = nc(delta)T

Direction of heat transfer

Heat goes from hand to object then it feels cold (Endothermic feels cold); Heat goes from object to hand then feels hot (Exothermic feels hot)

Heat conduction

Heat is transfered by conduction from high to low T regions; The rate of heat transfered (H) = k (change in T) / distance; Better thermal conductor has a larger k; Tile has a larger k than carpet, thus feels colder; Heat transfered from body to carpet (although at same T); Carpet has a lower k and is a better thermal insulator

Heat of Combustion

Heat realeased when one mol of a substance is completely burned. A higher heat of combustion means a structure is less stable, as it has a higher energy to begin with (More energy is given off)

Solution

Homogenous mixture of two components; Pure water is not a mixture becasue H2+O2 -> H2O; Gasous/liquid/solid (Most commonly solid dissolved in liquid)

Spring constant and PE stored in a spring

Hooke's Law: F=-kx ; PEspring = 1/2kx^2

Heterogenous vs Homogenous catalysts

Hetergenous catalysts involve the adsorption of reactants onto the surface of the catalyst and provide higher reaction rates with increased surface area. Homogenous catalysts is in the same phase as the reactants and can affect the rate of reaction because higher solubility can increase the interactions between reactant and catalyst species in solution

Organic solvents in extraction

Hexanes, Toluene, Dichloromethane, Diethyl ether, Chloroform, Ethyl ester, Ethyl acetate, Methylene chloride

Frequency of sound

High frequency = high pitch; Low frequency = low pitch; Frquency is a feautre of sound waves while pitch is a psychological phenom; Human hearing 20Hz-20,000Hz (higher pitch diminish with age)

Ksp

High solubiltiy if high Ksp; Low solubility if low Ksp; No compound is truly insoluble; Use Ksp to determine max numbner of mols of solute taht can dissolve in solution; Ksp=(Cation)(Anion); Ksp is unique to each solution is value differs from 1

When do gases behave ideally?

High temperature & low pressure; Volume is insignificant, elastic collision, no forces of attraction

Frequency in sound

High-frequency = high pitch; low frequency = low pitch

T and P on Solubility in Solids

Higher T lead to higher solubility for solids in ENDOthermic dissolution; Higher T leads to lower solubility for EXOthermic dissolution

T and P on Solubility in Gas

Higher T leads to lower solubility

Current intensity

I = Q / t -> Q = neAd / t -> Q is equal to the charge per electron * Avogadro * # of mols

Sound intensity inverse square law

I is inversely proportional to distance squared

Vacuum distillation

If boiling point is high, a vacuum is used to lower atmospheric pressure in order to lower the boiling points of all substances involved

How to tell the difference between Ionic & Coordinate bonds?

If the interaction involved a group 1 or 2 metal ion that did not have available d-orbitals, that would suggest an ionic bond. However, metal coordination complexes can form coordinate covalent bonds wherein the ligand acts as a Lewis base (e- donor) and the central metal acts as a lewis acid (e' center)

Salt Bridge in Electrochemistry

If there was no salt bridge, the accumulation of negative (cathode) and positive charge (anode) would generate a high electrostatci potential; As the magnitude of Q (charge) increases, it will require more and more electrostatic potential energy to transport electrons to/from electrodes. The energy requirement would exceed the voltage of the cell

Periods and Destructive Interference

If two waves are 1/2 period apart, they will destructively interfer

Surface tension & Water Droplets

Imbalance of IMFs at surface that makes its surface act as a thin, elastic film. Arises from cohesive forces (b/w like molecules) in a fluid. Water molecules at the surfae of water droplets experience a net inward force, decreasing surface area of the water and making a spherical shape

Deuterium labeling

Impacts the reaction rate, as heavier isotopes result in a greater energy requirement to break the associated bond

Which solution is more concentration in concentration cell?

In a concentration cell, the anode is less concentrated & the cathode is more concentrated. Want to increase the anode solution, so oxidation takes place at the anode.

Venturi Effect

In a vertical pipe, the higher the water level, the greater the pressure, the lower the velocity, and the greater the area underneath Lower area -> Higher velocity -> Lower P; Continuity and Bernouilli's equations

Adsoprtion vs. Solubility

In chromatography, adsorption is defined as how well a component of the mixture sticks to the stationary phase, while solubility is the property of how well a component of the mixture dissolves in the mobile phase. Higher adsoroption to polar -> More slowly; Higher solubility of compound in mobile phase -> More faster

Contrast Agents

Increase MRI signals by increasing the relaxivity of water molecules. These agents can be used to monitor biologicla processes. Example of a contrast agent is Gd. Gd coordinates with water.

What affects basicity of amines?

Increase resonance means more stable and less basic. The N atom that is the most basic is the one that does NOT participate in resonance. Least stable = Most Basic. EWG make it less basic, while EDG make it more basic.

What does doubling imply in percentages?

Increasing by 100%

Overtone of Closed Tube Resonator

Increasing frequency such that multiples of half a wavelength result in standing waves. The first overtone of a closed tube resonator is called the third harmonic

Indole, Imidazole, Guanidinum

Indole: Tryptophan, Imidazole: Histidine, Guanidinium: Arginine

Relationship between Amplitude, Intensity & Distance

Intensity proportional to amplitude squared; Intensity indirectly proportional to distance squared; Amplitude indirectly proportional to distance

Electromotive Force

Intrinsically related to the physical dimensions and composition of the battery; the magnitude of the electromotive force is indepedent of internal resistance

Electrical conductivity and resistivity

Inversely proportional; Metal has high conductivity and low resistivity; Insulator has low conductivity and high resistivity

Iodine Titration

Iodine + Starch -> Dark Blue

Solubility vs. Ionization

Ionization: MgCl -> Mg2+ + Cl- (Elecrolyte conduct elecity in solution) Solubility: Non electrolytes can also dissolve too without ionization (Don't break apart but do dissolve)

Hydrophobic interaction column

Ions (Na+, K+) strengthens hydrophobic interactions between column and solute. Salt promotes interaction between hydrophilic and hydrophobic regions of the protein and the medium by reducing the solvation of the sample moleucles and exposing their hydrophobic regions. The amoutn of salt needed to promote binding is inversely proportional to the hydrophobicity of molecules.

Spectator Ions

Ions that do not participate in the reaction. Commonly, the most soluble compounds like Na+ and NO3- do not form precipitates with commonly encountered ions and thus are spectator ions

Turbulent Flow

Irregular flow with random variations in pressure. Reynolds number is directly related to the velocity and density of the fluid and inversely related to the visocity. Higher density, higher velocity, lower viscotiy would lead to a more turbulent flow (increase T -> lower viscocity -> more turbulent flow)

Thermodynamic Vs. Kinetic Product

Irreversible reactions are under kinetic control, which favor products whose pathways have the lowest activation energy. Reversible reactions are under thermodynamic control, as they favor the most stable product.

Benefits of Methanol

It is easy to make methanol anhydrous. During distillation, water can be removed

Net fluid filtration

Jv = (Pc - Pif) -> Difference in hydrostatic pressures with capillary fluid hydrostatic pressure - insterstital fluid hydrostatic pressure

Starling equation

Jv = K ((Pc-Pif)-(Osmoticc - Osmoticif))

Distribution Coefficient Extraction

K is the ratio of solubility of a compound in organic layer to aqueous layer. Water can remove highly polar substances (inorganic salts, strong A/B, polar, low MW compounds). Acid can remove organic bases (amines).

Kinetic energy of water flowing

KE = 0.5 * p * v^2 * V

KE gas particles & Boltzman Constant

KE = 3/2kT for monoatomic ideal gas; Boltzman's constant; Average translational kinetic energy at a given temperature

Kb, Ka, Kw

Ka*Kb=Kw & pH+pOH = pKw & pKa+pKb=pKw ; If Ka>Kw, then ignore water dissociation

A molecule's charge or polarity may be modified to increase or decrease affinity for a solvent. DNA can be precipitated by neutralized its charge. Hydrophobic into organic layer and polar/charged into aqueous layer.

Kinetic product has a lower energy barrier and a higher final energy; Thermodynamic product has a higher energy barrier and a lower final energy (more stable)

Equilibrium Partial Pressure

Kp = (Pproducts)^m / (Preactants)^n

Resonance in Open Pipe (Both ends)

L = (n)/2 * Wavelength

Resonance in Open Pipe (One end)

L = (nodd)/4 * Wavelength

Lactone vs Lactam

Lactone is a cyclic intramolecular ester derived from a hydroxy acid while a lactam is any class of cyclic amides (N analogs of lactones)

Where are metals plated in electrolysis?

Metals are plated onto an electrode where their aqueous ions are reduced to from the solid metal. Happens at the cathode!

Myopic Eye Near Point & Far Point

Lens is too strong. Eye is too long. Near point is closer than normal eye. Far point is closer than normal eye. Optical power of a myopic eye exceeds what is required for the axial length of the eye. As a result of the increased optical power, the myopic eye near point is smaller than normal.

Hyperopic Eye Near Point & Far Point

Lens is too weak. Eye is too short. Near point is farther than normal eye.

Linear Polarization of EM Radiation

Linearly polarized waveforms are associated with oscillations that occur in a particular orientation in the corrdinate system. A linear polairzatin filter blocks electric fields aligned perpendicular to the axis of polarization (50% of total intensity); I = Cos^2theta * Io

Torque due to gravity

Lmg(sin theta)

Decibals

Log scale that relates the percieved loudness of a sound to its actual intensity. For each 10 fold decrease, sound intensity decreases by 10dB. A sound that is 10 times more intense is twice as loud. A 100 fold decrease in intensity corresponds to a decrease in 20dB and a sound that is 1/4 as loud.

Diffraction of Long vs. Short Wavelengths

Longer wavelengths diffract more than shorter wavelenghts. If the hole is smaller than the wavelength, then the wavefronts coming out of the hold will be circular. (BUT, shorter wavelengths bend more in a denser medium!)

Meso compound

Many chiral center, but symmetry and thus achiral

Lead Acid Battery

Low energy density; Pb (s) & PbO2 seperated by H2SO4; Pb and PbO2 both create PbSO4; Both half reactions have the same products

Series of Spectra

Lyman (UV): n=1; Balmer (visible) n=2; Paschen (infared) n=3

Mechanical Advantage

MA = Force out / Force in = Distance in / Distance out; For inclined planes, MA = hypot / height

NMR

Magnetic pulse to displace atomic nuclei; nuclear oscillation; Non invasive; Observe chemical reactions

How does mass affect friction?

Mass is not a factor in overcoming static friction; Fnet = (mgsintheta) - (Usmgcostheta) ; As both m and g cancel out, they do not depend on whether something will slide down an inclined plane

Momentum

Mass*Velocity -> Velocity only changes momentum, not inertia

Water-based spirometer

Measure lung capacity. Following exhalation, the volume of water inside the spirometer chamber and the pressure of the air inside the chamber change. To calculate the pressure of the gas: Total pressure - water vapor pressure. The pressure is being measured over a volatile liquid. When you blow into tube enclosed in a closed vessel, the pressure from the gas will push the water level down.

Calorimetry

Measures heat transfer from changes in temperature. Isolated system. If ice is used in the calorimeter instead of water, the heat from the combustion will go to melting the ice and thus the temperature of the water would begin at a later time. The amount of heat released from a combustion reaction depends on the mass.

Extraction

Method used to isolate a chemical using immisicible solvents. Organic solvent is a nonpolar solvent. Aqueous solvent is a polar solvent. You can boil away the organic (low BP) after extraction has taken place.

Microgravity enviornments

Microgravity enviornments promote cartilage decompression and elongation. The spinal cords do not support any weight

Purpose of washing with Brine

NaCl may be used to remove water from organic layer

Strong base

NaOH, KOH, Ca(OH)2, NH2-, CsOH -> Kb greater than 1

Representative Elements

Name for main group elements (Groups 1-2) and (Groups 13-18) & have group named A; Transition metals are groups named B

Isothermal

No change in Temperature; Q = W; All the heat is used to do work; Heat can change

Doppler Angle of Insonation

No doppler shift is obtained as 90 degrees, since cos90 = 0. The optimal doppler angle is when the ultrasound beam is aligned perfectly with the direction of blood flow (Parallel or antiparalel with velocity) & cos0 = 1

Plane mirror

No focal point; Always produce virtual images behind the mirror that appears to be the same difference

Adibiatic

No heat is lost; U = -Work; All the internal energy is used to do work; Temperature can change; Temperature falls during adibiatic expansion & Temperature rises during adibiatic compressin

Ionic compounds

No net charge at all; Polyatomic ions naming: Ion with lesser charge is "ous", greater charge is "ic", if H is introduced then "bi" or "dihydrogen"; Monoatomic ions use "ide"; Oxyanions (polyatomic oxygen anions) use prefix and suffixes (hypo, ite, ate, per)

Properties of Ideal Fluid

No viscosity, Laminar flow, Incompressible

Do gases form Hydrogen bonds?

No, H-bonding does not occur in the gasous state. Gases can form covalent bonds to form diatomic molcules.

Meso Isomers

Non-optically active members of a set of stereoisomers, at least two of which are optically active. This means that despite containing two or more stereogenic centers, the molecule is not chiral. If a symmetrical molecule has 2 stereocenters, there will be only 3 stereoisomers.

Chromatography

Nonpolar solvent and polar stationary phase

Parts per Million (ppm)

Normalizes fractions/concentrations to a total mass of one million. ppm = mass solute / mass solution * 10^6. ppm = mol fraction * 10^6. 1ppm = mg solute / kg solution

Nucleophilic addition vs electrophilic addition

Nucleophilic addition is adding a nucleophile (Grignard) to an electron-deficient species (carbonyl carbon). Electrophilic addition is adding an electrophile to a double or triple bond (Addition to a double bond, markovnikov)

Coordination number

Number of coordinate bonds, where coordinate covalent bonds are formed between two atoms when both of the shared electrons are donated by the same atom. Usually formed between electron poor metals and molecules called ligands that contain one or more electron electron fich atoms with available lone pair electrons. The coordinately bonded metal and ligands are called complex

Hydrogen Deficiency Formula

Number of double bonds = (2C+2-H) / 2

Degrees of Unsaturation

Number of double bonds and rings. (2C + 2 + N - H - X) / 2

Normality (N)

Number of equivalents per L of solution; Acid/base chemistry; N = M(acid) * (#acidic protons per molecule); N = M(base) * (#OH- ions)

Molality (m)

Number of mols of solute per kg of solvent; In dilute, N = m, becasue kg of solute has not meaningful impact on L (1L water = 1kg; different density will make N not equal m)

Molarity (N)

Number of mols per L of solution; mol/L; To make a solution, need to keep the ratio of xmol solute : 1L of solution

Density and buyoancy

Object flotation is determined by density Less dense object will rise more quickly

Newton's Second Law

Only described unbalance or net force. It can describe constant and variable forces.

Osmotic Pressure

Osmolarity = iMRT; Moves from lower osmolarity to higher osmolarity

Outer vs. Inner Hair Cells

Outer: Amplifies (3 rows) Inner: Directly innervate (stimulate) the auditory nerve (1 row)

Pressure Formula in Closed Static Fluid System

P = F/A ; P = Patmosphere + density*g*h ; Greatest pressure at lowest depth in a closed static fluid system

Power

P = IV P = I^2R P = V^2/R

Power, Energy, Work, Force Equations

P = IV P = E/t W = E = Fd P = Fv

Cyclic heat engine

PV Diagram will be a closed loop; Converts thermal to mechanical energy by transfering heat between Hot and Cold and doing work; QH = QC+W; Involves Isothermal and Adibiatic Expansions & Compression; RIGHT/DOWN is expansion; LEFT/UP is compression

Units for Viscocity

Pa*s

Dalton's Law of Partial Presssure

Partial pressure is the pressure that the gas would exert if it took up the same volume by itself; Pgas =Xgas*Ptotal

Diffraction grafting

Passage of light through an array consisting of numerous slits. Diffraction grafting may be used to determine the components of polychromatic (white) light and other mixed electromagnetic wavefronts. Diffractive grate composed of numerous slits with near-zero width similar to teh wavelength of incident light. Characterized by sharp & narrow & vary in height peaks.

Pressure for multifluids system

Patmosphere + density1gh + density2gh = Ptotal

How to produce a free amino acid?

Peptide bond hydrolysis, strecker synthesis, Gabriel synthesis WITH malonic ester

What type of reaction is a phase change?

Phase change is a physical reaction, not a chemical reaction. Thus, covalent bonds are not broken, only hydrogen bonds. More energy is needed to evaporate water than to melt ice, as hydrogen bonds are broken. Hydrogen bonds are types of dipole-dipole interactions, not a true chemical bond.

Mnemonic for Lens and Mirror

Positive images are Real and Inverted. Negative images are Virtual and Upright.

Galvanic cells

Positive redox potentials; Spontaneous direction; Anode is negative & Cathode is positive; Daniel OR Concentration

Positron vs Proton emission

Positron is an anti-particle of an electron, with same mass as an electron but a positive charge (Emission = radioactive beta-decay). Proton is more passive, has a positive charge (Emission = Light emission)

Intensity of sound

Power delivered by sound over a given area; Intensity is proportional to amplitude squared (dB) Loudness of sound; Loudness is our perception of sound; Intensity of the sound wave is proportional to amplitude^2; Decibal scale; Db = 10log(I/reference min); 40dB higher means 10^4 more intense

Pressure and Temperature at High Altitudes for Gas

Pressure decreases and Temperature decreases at high altitudes

Stationary fluid vs Flowing fluid pressure

Pressure increases equilibrate quickly via Pascal Principle; (Flowing fluid follows Venturi effect so a faster velocity means lower pressure)

Vapor Pressure

Pressure of the vapor phase existing immediately above surface of liquid; Higher vp indicates a larger number of solvent particles were able to escape the liquid and enter theh gas

Surface tension

Property of surface of a liquid that allows it to resist an external force (adhesion) due to the cohesion of molecules in the liquid

Surface Tension Definition

Property of surface of a liquid that allows it to resist an external force. Small objects float on surface of liquid. Surfactant lowers surface tension of lungs, allowing easy expansion upon inspiration.

Pyridine vs Pyrimadine

Pyridine is 6C ring with 1N. Pyrimadine is 6C ring with 2N

Sn1 Reactions

Racemic mixture thus no net rotation of polarized light

Radiation Energy

Radiation Energy is directly related to the T of object

Rate Law

Rate = k (A)^x (B)^y

Fick's law of diffusion

Rate of diffusion of a gas = DA(Partial Pressure Difference) / Thickness; As partial pressure increases from diffusion, the partial pressure difference will decrease and thus the rate of diffusion will decrease ; The rate of diffusion of a gas across membrane is proportional to partial pressure difference

Precipitation of DNA

Reacting DNA with a cation can interact with DNA's phosphate group, leaving the DNA too polar to remian in less soluble ethanol. Ethanol is commonly used as a solvent to precipitate DNA, while sodium acetate is used to make DNA more polar

Temperature & Solubility for Gas

Solubility decreases at T increases; HCl, NH3, SO2 are gasses at St. P; KE of gas solutes increase and increase tendency to espace

Alkali metals

Reducing agents, single valence electron, form hydrides (basic) when bound to hydrogen, react with water

Tollens and Benedict Reagents

Reducing sugar; Silver mirror will form for Tollens'; Reducing sugar will reduce Cu2+ + e- -> Cu+ causing a green color

Isotopes

Same chemical properties (electron configuration) but different physical properties (number of neutrons)

Attenuation

Sound dampening; Negleted unless otherwise stated

How does a refridgerator work

Remove heat from cool internal enviornment it into warm, external enviormnet; Work is done by compressor to turn refridgerant into a liquid; Liquid flows through refridgerator & absorbs energy; Gas releases heat to external enviornment

Molecular weight of a sinlge molecule

Represented by amu

Cp vs Cv

Requires more energy to raise to a specific T if the volume is changing; Cp>Cv; Temperature can only change if P or V change (at the same number of mols)

Resistors in parallel

Requiv = r/N ; Increasing N decreases r

Identical chemical species

Same elemental composition, same number of electrons, same orbital bonding configuration

Retention Factor in TLC Plate

Retention factor is the distance migrated by the compound divided by total distance traveled by solvent. It depends on solvent system, temperature, and adsorbent

AC Current

Reverses its polarity at a constant rate (Ex: 1V to -1V) in a sine-wave pattern. The average EMF of an AC circuit is zero. Usually measured as a rms value instead (V/sq(2))

Circular Polarization

Rotation of polarization observed when two transverse waves with equal amplitudes and perpendicular linear polarization propagate out of phase with one anohter by 90 degrees.

Entropy Equation (Boltzman's Constant)

S = klnW ; where W is the number of energetically equivalent ways to organize the components of a system

Streaking on TLC

Sample too concentrated, Overspotting, Many components on the sample

Saturated Solution

Saturated when max amount of solute into solution is added (Precipitate if add more); Unsaturated contain less than maximum amoutn of solute; Rate of dissolution equal to rate of precipitation

Reducing agent BH3

Selectively reduces carboxylic acids to alcohols. 1. BH3*THF 2. H2O

Thermosensation

Sensation of temprature by an organism

Fractional Distillation

Seperate compounds that are less than 25 degrees celcius. It uses a fractioning column and a condensor to provide a larger surface area on whicih the vapor of the distallate can condense before distilling into the recieving flask

Vacuum Distillation

Seperate compounds that have bp greater than 150. It uses a vacuum to connect to apparatus to avoid decomposition and lower the pressure + bp.

Which amino acids undergo phosphorylation?

Serine (S), Threonine (T), Tyrosine (Y), Histidine (H)

Sec-butyl group

Side chain of Isoleucine

Metalloid

Silicon and boron share characteristics of metals and nonmetals. They are semi-conductors, which means they both insulate and conduct electricity

Kinetic friction and direction of acceleration

Since friction opposes sliding, kinetic friction causes sliding objects to decelerate. The magnitude of deceleration is calculated using : F = ma ; a = -ukmg / m = -ukg

Isolelectronic

Species with the same electron configuration (same number of electrons). Isoelectronic atoms with a greater number of protons will have a higher Zeff

Conformational Isomers

Stereoisomers that differ by rotation about one or more single bonds, usually represented using Newman projections. Same connectivity and can be interconverted by rotation of sigma bond. They are identical except for bond rotation. They are the same compound.

Strength of Multiple Lenses

Strength of a convex lens in sequence = S1+S2

Reducing Agents

Strong: LiAHl4 (CA to primary alcohol), DIBAL (CA to aldehyde) Weak: NaBH4 Other: H2 with Ni, H2 with Pd, Hydrazine, B2H4, CO, C, Lindlar's, Zn(Hg), Metals

Oxidizing Agents

Strong: Na2Cr2O7, KmnO4 Weak: PCC Other: O2, H2O2, Halogens, H2SO4, HNO3

Why does shift in frequency of percieved sound occur?

Successive sound waveforms are emitted further from the observer

Electron Acceptors for Anaerobic Repiration

Sulfate, Phosphate, Nitrate, CO2 Fe3+ (Inorganic), DMSO (Organic)

Length of sigma bond

Sum of atomic radii of bonded atom; Atoms with smaller atomic radius will have stronger bond; Atoms will larger atomic radius have larger bonds (decrease across row and increase down column)

Period of Pendulum

T = 2π√1/g : the period of a pendulum is equal to two pi times the square root of the length of the pendulum divided by the acceleration due to gravity

Kinetic Energy & Absolute Temperature

T is proportional to the sum of the KE of each molecule divided by the quantity of molecules

Boiling point elevation

Tb = iKbm; Tb is amount bp elevated, i is Van Hoff, m is molality; Adding solute increases bp

Pseudo First Order

Technically a second order, but behaves like first order. One of the reactants is present in excess, that it does not affect the reaction rate.

Freezing point depression

Tf = iKfm; Adding solute decreases freezing point

Conservation of Energy Launching

The KE of an object launched upward into gravity gets changed to PE, as the radial distance increases

Paramagnetism

The angular momentum of unpaired electrons with a single spin state creates a magnetic dipole moment. Electrons are unpaired and are not in the same orbital

Second Ionization Energy

The energy needed to knock off the second valence electron. Ionization energies make a large jump when the electron is being removed from a noble gas configuration. Ex: 2nd IE of Na

How does temperature affect Ka?

The dissociation of an acid is usually an endothermic process. Thus, as temperature increases for an endothermic reaction, product is favored and Ka increases (pKa decreases).

Doppler Shift for Ecolocation

The echolocator can be considered the source and the reciever. The relative vecloity of the source and reciever away form eachother can be considered doubled even though they are the same object. The Doppler effect occurs twice for ecolocation so higher change in frequency (change in f/f = 2v / c ; where v is the relative velocity.

Entropy of Reversible Reaction

The entropy of a reversible reaction is zero

Larger vs Smaller Focal Length

The larger the focal length, the narrower the angle of view and the higher the magnification. The focal length depends on the index of refraction of the medium.

Mass Spectrometry

The largest number is whole fragment & complete monomoer; The number next to it in parenthesis is the relative abundance; If there is a larger relative abundance then it is more stable; Can't refer boiling point from mass spectrometer alone; In mass spectrometer, double bonds are not usually broken

Fundamental frequency

The lowest, and usually most intense, frequency of a complex sound; most often perceived as the sound's basic pitch

Regioselectivity

The making or breaking of chemical bonds in one direction over all other directions that are posible. Forms constitutional isomers. (Ex: BH3 across the double bond adds OH- to the less substituted side)

Rollercoaster Circular Motion

The minimum speed needed to stay on the track is when the Normal Force is equal to 0; Fc=Fg; v = sq(g*r); Minimum rollercoaster height = 5r/2

Net force on dipole in capacitors

The net force on the dipole is zero. Capcitors create a constant electric field across their plates, so the force exerted on + end of the dipole will be equal and opposite to the force on the - end of the plate.

Gas Chromatography Retention Time

The order of GC peaks has to do with the polarity of the individual molceules OR boiling point. Reducing the temperature then reduces energy within molecules. The molecuels are held up inside gas column longer. There is a longer in retention time, more spaced out between the peaks so resolution would increase. Mobile is inert gas, while polar is stationary phase (More polar will have longer retention time).

Percieved Color of Light

The percieved color of a substance is complemtary to the color of the wavelength that is maximally absorbed by that substance (Orange = Blue, Yellow = Violet, Red = Green). The color of a substance is determined by the wavelengths of light it absorbs, which is determined by the electornic structure of the molecule

Diver's Wetsuit and Buoyancy

The pockets of air that get compressed as the diver descends causes a decrease in V of the wetsuit which means a decrease in density (as mass is constant) of wetsuit and a decrease in Fb; Fb is proportional to the volume of the displaced object; Density of liquid never changes; Swimming deeper will cause sinking

Raoult's law of Vapor Pressure

The presence of a solute decreases the vapor pressure; P = Xa*Pa (pure solvent)

Dynamic Pressure

The pressure associated with the movement of a fluid Static P - Stagnation P = Dynamic P = 1/2(density)(v^2)

Stagnation vs Static Pressure

The pressure at a point in a fluid is called the 'static pressure'. The 'stagnation pressure' is the pressure that the fluid would obtain if brought to rest without loss of mechanical energy. The difference between the two is the 'dynamic pressure'.

What affects rate of conduction?

The rate of heat transfer through solids depdents on conductivity, T, thickness, area. Conduction increases with denser materials.

Law of Mass Action

The rate of reaction is proportional to the molar amount of each reaction component raised to the power of its reaction order. An increase in the substance that contributes more to the reaction rate will increase the rate of reaction.

Frost Diagram

The slope of the line segment joining two species equation the standard recution potential for the couple. Frost diagram can determine reactions unstable towards disproportionation. Graph is NE (Delta G = -FNE) divided by Oxidation number.

Speed of flow in aorta vs capillaries

The speed of flow is larger in the aorta since the total cross senctional area of all the capillaries is greater than the total cross sectional area of the aorta (Even though the cross sectional area of the aorta is greater than a single capillary)

How do fundamental frequencies and wavelengths change with T?

The speed of sound increases with increasing T. The fundamental wavelength stays the same, since length of tube does not change. The fundamental frequency increases.

When is entropy maximized?

The system is at equilibirum & System can't do work. Delta G = 0. There are no energy gradients within the isolated system so energy is maximally dispersed. With no free energy change, the system is unable to perform work.

Thermodynamic Enolate vs. Kinetic Enolate

Thermodynamic enolate forms more stable product & Requires small base. Kinetic enolate forms less stable product and requires bulky base (LDA)

Electrostatic potential energy & Electric Potential

U = Vq = qEd; V = Ed

Diethyl Tartrate

Three stereoisomers exist. The R,R and S,S isomers are enantiomeric, being mirror images. The meso stereoisomer is not chiral. It is a stereoselective reagent

Porosity

To estimate scaffold porosity, need a ratio that describes how much substance it absorbs to estimate how much increase in weight after being immersed. (Weight after immersed - Weight after drying ) / Initial Dry Weight

Specific gravity formula

To find percent of volume above water (when sg<1) = (1-Sgobject/sgwater)*100%

Inertia & Torque Equation

Torque = I*alpha = Change in L /. Change in T I = (0.5)*M*R^2 (Disk) OR I = MR^2 (Hoop)

Energy and flux for a beam of particles

Total Energy = (# particles) * Energy ; Flux = (# particles per unit time / Area) Magnetic flux = B*A*cos(theta) Electric flux = EAcos(theta) = q / Eo

Propertides of Non-Ideal Fluid

Viscous, Turbulent Flow, Compressible

Surface Tension Formula

Ts = F/d Surface tension decreases as temperature rises, as fluid molecules can more easily break IMFs. Surface tension decreases as SA rises

Aldol reaction product

Two carbonyl compounds react to form alpha, beta unsaturated ketone or aldehyde

Energy in capacitor

U = 1/2QV = 1/2CV^2 = 1/2Q^2/C

Thermodynamics Equation

U = Q +/- W ; -W means work done by system (Expanding gas); +W meanas work done on system (Compressing gas)

UV chromophores

UV light excites electrons of UV chromophores to a higher E state in TLC. Include double and triple bonds, C=O, nitroso groups, alkyl halides, and conjugated systems

Water as the solvent of life

Universal solvent, high specific heat capacity, adhesion & cohesion forces, polarity

Goldman-Katz Equation Membrane Potential

Vm = -60mV * log (Naout+Kout / Nain + Kin); Total amount of current flowing through potassium equals total amoutn of current flowing through sodium channel; More sodium channels are open, so twice as much current flows through an individual potassium than sodium channel

Autoclaving

Used for sterilization; Bringing material to a T over 120 degrees and a P of over 2atm; Kills

Function of ebulliator?

Used to prevent superheating by releasing air bubbles into a liquid which rise and break the surface tension of the liquid, preventing heat from becoming trapped

Echocardiography

Uses short wavelength / high frequency ultrasound to generate image measurements of the heart, as shorter wavelengths are useful in imaging finer structures. Shorter wavelenghts are more likely to be to be absorbed by tissue and generate images

Lucas Test

Using ZnCl2 and HCl to test for the presence of secondary and tertiary alcohols. Formation of insoluble compound due to Sn1 reaction. Sn1 reactions produce stable carbocation intermediates.

Doppler Effect Signs of Source + Observer

Vobservor is positive if observor is moving towards the source; Vsource is positive if source is moving away from observer; Moving in the right direction recieves a positive value ; If moving TOWARDS eachother -> f'>fo ; If moving AWAY eachother -> f'<fo

Ideal Gas Deviation formula

Van Der Waals: (P+an2V2)(V−nb)=nRT; Larger a and b means more deviation

Colors of Visible Spectrum

Violet (380-450) - Blue (450-490) - Green (490 - 565) - Yellow (565-590) - Orange (590-650) - Red (650-740)

Why would a compound need to be produced in situ?

Volatile compounds, such as Iodine, may need to be produced in situ in order to not lose any compound. Iodine can be then used in a redox reaction, reacting with starch after reaching the endpoint.

Piezoelectric effect

Voltage generating a current through the crystal (Electrical energy) and the crystal vibrating (Mechanical energy)

Cone

Volume = 1/3*pi*r^2*h

Dilution Factor

Volume of Standard Solution / Volume of Stock Solution = Concentration Stock Solution / Concentration of Standard Solution = Volume Final (Aliquot+Dilutent) / Volume Initial; Diluted Concentration = Dilution Factor * Initial Concentration; For more than one dilutions, multiply the dilution factors together

Potentiometric Titration

Volumetric titration method in which the potential between two electrodes is measrued (reference and indicator electrode) as a function of the added reagent volume. Reference electrode is usually a calomel electrode and indicator ususally a silver electrode. Electrodes are attached to a voltmeter or pH meter. E cell = E indicator - E reference + E junction

Velocity root mean square

Vrms = sq(3RT/M) ; Vrms increases as M decreases

Units for P-V Work

W = P(delta)V, where V is measured in m^3

Work done by nonconservative force

W' = deltaE = deltaK + deltaU The magnitude of the work done by a nonconservative force depends on the total distance through which the force is applied.

Purpose of washing with water & ethanol

Wash with deionized water will remove soluble byproducts. Washing with ethanol after helps remove adsorbed water, and since ethanol has a higher vapor pressure than water, it faciliates drying of the solid.

What is the best leaving group?

Weak Bases! As electronegativity increses, basicity decreases. As size increases, basicity decreases. Thus, the best leaving groups are to the right of the periodic table and down the group.

Tensile vs. Compressive Forces

Weight can act as a compressive force or as a tensile (pulling) force. Tensile forces may lead to the elongation of objects under tension. Tension is a force that results from an object being pulled in two direction. The effects of gravity can be experienced as tension or compression

Specific gravity (weight ratio)

Weight of substance / Weight of equal volume of water; Fg/Fb

Newton's First Law

When a mass experiences a net force, the mass will accelerate in the direction of the force. When no net force is applied, its velocity is unchanged. Thus, an object will accelerate to a velocity when a force is applied and will continue at the same velocity when the force is removed

Burning candle and water rising Experiment

When candle burns, O2 is limiting reagent -> O2 is consumed and more moles of CO2 gas are produced -> n increases so P increases -> After T decreases, P finally decreases -> At the end of experiment, there is less n but same V, R, T -> Due to less n, P decreases -> To compensate for P decreasing, water level needs to rise

What happens when object distance is large?

When do is large, di = f & the image is small

Why is acetal protection more thermodynamically favorable?

When forming cyclic acetal, 1 diol produces 1 product. When forming acetal, 2 alcohols produce 1 produce. Thus cylic acetals are more favorable in entropy.

Decompression Sickness (DCS)

When going from high pressure to low pressure, a venous gas emboli can form. Nitrogen dissolved in the tissues forms bubbles as pressure decreases, Nitrogen does not have time to clear from blood & instead seperates out of blood and forms bubbles in tissues.

Unstable Equilibrium

When set off balance, tends towards a position other than equilibirum point

Boiling chips and scratching flask

When transitioning from liquid to gas, the liquid needs nucleation sites and places to start forming bubbles

ICE Table

When we don't know if all the reactant is used up, the change will be dented as x; If we want to find equilibrium constnat use ICE; If there is a strong acid or base, then we can assume all reactant gets used up

How to x-rays produce images

X-ray images are produced by high eneergy electrons. The energy from x-rays is absorbed by different rates by different parts of the body. The detector on the other side of the body picks up the x-rays after they have passed through and turns them into images. Energy from the electrons produced by an x-ray machien is given up as heat in the target organ (target organ = high thermal conductivity)

Mol fraction of gas

Xgas = ngas / ntotal

Hydrolysis of an acetal

Yields 2 alcohols and a free aldehyde

Types of Acid-Base Neutralization

a) Acid reacts with a base containing hydroxide (OH) to produce water and salt b) Acid reacts with a base containing carbonate or hydorgen carbonate (HCO3) to produce water, CO2, and salt

Types of Single Displacement

a) Solid reacts with a metal solution (metal plates out) b) Solid metal reacts with an acid (produce hydrogen gas) c) Solid metal reacts with water (produce hydrogen gas and hydroxide metal)

Square Planar Hybridization

dsp^2; Transition metals

Trigonal bipyramidal Hybridization

dsp^3

Frequency, period, velocity (Circular motion)

f = 1/T ; v = (2*pi*r)*frequency = omega*r ; 1 rev = 2*pi*r meters ;

Arrhenius equation

k=Ae^(-Ea/RT)

Difference between pKa and pH?

pH is a measure of concentration of hydrogen ions in an aqueous solution (acidic or basic). pKa is more specific, as it helps predict what a molecule will do at a specific pH (dissociation); When pH increases more than 2.0 pH units above pKa, then the major chemical in solution is conjugate base

Heat exchange equation

q = mcat Heat flows from hot to cold; Heat gained by water = heat lost by object

Trigonal Bipyramidal Hybridization

sp^3d

Square Pyramidal Hybridization

sp^3d^2

Octahedral Hybridizaiton

sp^3d^2 OR d^2sp^3

sp^3d^2 vs. d^2sp^3

sp^3d^2: Atomic orbitals of the same electron shell (Nonmetals); d^2sp^3: Atomic orbitals of two electron shells (Transition Metals)

Time of flight equation for projectile motion

t = 2*velocity / g ; time in flight is inversely proportional to gravity

Dipole moment formula

u = qd q = magnitude of charge d = distance b/w centers of charge dipole = polar no dipole = nonpolar

Sound wave velocity

v = sqrt K/density; where K is coefficient of stiffness for bulk modulus; sound waves travel faster in solids; increasing density causes sound wave speed to decrease

Rate of Effusion

vrms = sq(3RT) / M ; Rate of effusion is directly proportional to the square root of the T

Terminal velocty

vterm = mg/kA; kvtermA = mg; Terminal velocity inversely proportional to cross sectional area