ap chem 2020 exam (!!!)

What charge does Al typically have in ionic compounds, and why?

+3, because it has three valence electrons. it becomes more stable when it loses 3 electrons and has no empty orbitals

if reaction wants to go towards products

-Gibbs must be NEGATIVE!!!!

If the reaction wants to go towards reactants (in reverse)

-Gibbs must be POSITIVE

things that have no effect (changes to a system): (equilibrium)

-add inert gas -add/remove a liquid or a solid-add catalyst (although it speeds it up)

Evidence that a chemical reaction has occurred

-bubbles (gas formed) -color changed -change in temp (not getting lighter bc that just means dilution) -change in odor -cloudy

chromatrography

-cant be separated by flirtation, take advangtage of imfs -larger particles will move more slowly -partiles with a polarity that matches the solvent, it will move further -paper is nonpolar

factors that govern rates of reaction

-concentration, (rate and concentration are directly related) -temp (temp and rate are directly related)-catalyst, with a catalyst rate increases -as reactant surface area increases, rate increases

"what type of reaction is this" options

-double displacement -combustion -single displacement -oxidation reduction -acid-base -decomposition -combination (probs will be oxidation reduction is my guess)

rules about k

-only depends on reaction stoichometry, not its mechanism -independent of initial concentrations -unaffected by other substances, as long as they dont react with p and r -varies with temp-written without units -NEVER includes pure solids or liquids

Distallation

-seperates parts of a mixture based on different boiling points -heat mixture to a temp that is inbetween the two boiling points of the liquids -lower boiling point will evaporate then condensate into separate tube

emission of light within elements

-shows that elements only accept certain amounts of energy

characteristics of molecular solids

-soft (bc of weak IMFS) -low melting points -insulator and do not conduct electricity well -stronger intra than inter

if u increase concentration of a reactant or product

-the system is now stressed on that side -shifts away from the added reactant to relieve the stress

if u decrease concentration of a reactant or product

-the system now has less than it should on that side -shifts towards the removed reactant to relieve the stress

(e) In the following empty box, draw an appropriate number of each type of molecule to represent a possible new equilibrium at the lower temperature. H2(g)+I2(g)⇄2HI(g)

-there is one h2 molecule and one I2 molecule -there is twelve HI molecules

characteristics of network covalent solids

-very hard -high boiling points -not soluble, volatile, or conductive

At a certain temperature, SO2(g) and O2(g) react to produce SO3(g) according to the chemical equation shown above. An evacuated rigid vessel is originally filled with SO2(g) and O2(g), each with a partial pressure of 1atm. Which of the following is closest to the partial pressure of O2(g) after the system has reached equilibrium, and why? 2SO2(g)+O2(g)⇄2SO3(g)Kp≈2×105

0.5atm; because Kp is very large, nearly all the SO2(g) is consumed before the system reaches equilibrium, but an excess amount of O2(g)O2(g) remains at equilibrium. limiting reactant is O2. (think about limiting reactant when given these problems)

problems with kinetic molecular theory

1. do occupy space 2. do experience forces (gases with stronger forces and larger masses deviate the most from the ideal gas law)

how to know which way it shifts in dilution

1. it will affect the side with more moles more than the other 2.. plug in numbers to K expression for a normal concentration, then a lower concentration and see what happens

collision theory

1. molecules must collide to react 2. concentration affects rates because collisions are more likely 3. temp and rate are related 4. only a small number of collisions can react

photoelectric effect

1. only light at or above a threshold frequency will cause electrons to be ejected from a metal surface. 2. once threshold is reached, then the intensity (brightness) of the light determines how many electrons are admitted

Kinetic Molecular Theory

1. particles don't have volume 2. particles are in constant motion. the collisions of the particles with the walls of the container are the cause of the pressure 3. the particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other 4. the average kinetic energy of a collection of gas particles is assumed to be directly proportional to the kelvin temp of the gas -explains ideal gas law

how many isotopes were in this

3

The conversion of ozone to diatomic oxygen is represented by the equation above. Based on the data in the table above, what is the approximate average bond enthalpy for the oxygen-to-oxygen bonds in ozone? Type of Bond Average Bond Enthalpy (kJ/mol) O−O 150. O=O500 2O3(g)→3O2(g) ΔH∘rxn=−300kJ/molrxn

300 kj/mol

physical change

A change in a substance that does not involve a change in the properties but composition. only forces broken are intermolecular ex: filration, chromatograpy, distlation

chemical change

A change in matter that produces one or more new substances

polar covalent bond

A covalent bond in which electrons are not shared equally but one atom isn't strong enough to completely remove an electron from another.

Entropy

A measure of disorder or randomness.

alloy

A mixture of two or more metals

Amphoteric species

A species capable of reacting as either an acid or base, depending on the nature of the reactants. most common one is h2o

Which of the following identifies the reaction in which the number of successful collisions and reaction rate are independent of the orientation of the reactants and explains why?

A. The electron cloud is distributed symmetrically around the O atoms; thus the orientation of the two reacting O atoms during a collision is not a factor in determining the success of the collision and the reaction rate.

Beer-Lambert Law

A=ebc. e and b are usually held constant. in such cases, shows that concentration is proportional to absorbance (direct relationship).

The diagrams above represent two allotropes of solid phosphorus. Which of the following correctly identifies the allotrope with the higher melting point and explains why?

Allotrope IIII, because it has covalent bonds between the phosphorous atoms that are stronger than the dispersion forces between the P4P4 molecules in allotrope II.

atomic radii trend

An atom gets larger as the number of electronic shells increase (explains down a group). there is a greater nuclear attraction as protons increase, meaning that the nucleus attracts the electrons more strongly, pulling the atom's shell closer to the nucleus. As a result, the atomic radius decreases. ( explains across)

column chromatography

An impure sample is loaded onto a column of adsorbant, such as silica gel or alumina. An organic solvent or a mixture of solvents (the eluent) flows down through the column. weaker interactions are at bottom, stronger ones at top.

Infrared Spectroscopy

An instrumentation method of analysis that identifies bonds from absorption of the infrared radiation of different wavelengths. ex explanation: The absorption of infrared radiation leads to an increase in molecular vibrational level associated with the stretching of the carbonyl.

isotope

Atoms of the same element that have different numbers of neutrons

why is zn in h2o exothermic

Collisions between the water molecules and the surface of the Zn pellet will result in the transfer of energy, increasing the average kinetic energy of the water molecules.

Conjugate Acid and Conjugate Base

Conjugate Acid = Forms when a base gains a proton (opposite of the Bronsted Lowery Base) Conjugate Base = Forms when an acid loses a proton (opposite of a Bronsted Lowery Acid)** Conjugate Acids and Bases are found in the products side of the reaction

The graph above represents the data collected under certain conditions for the decomposition of N2O4(g) according to the chemical equation above. Based on the graph, at approximately which time is equilibrium established?

D, completely flat

differential rate law

Describes how rate depends on concentration. r = k (concentration of products). for each type of differential rate law, there is a integrated rate law.

The diagrams above use arrows to represent the speed of a gas particle. Which of the diagrams best represents the speed of the particles of a gas at a fixed temperature, and why?

Diagram 2, because the particles have a variety of different speeds. arrows = speed

ionization energy trend explained

Elements on the left side of the periodic table have low ionization energies because of they have less of attraction to the nucleus due to effective nuclear charge. There are more protons in atoms moving down a group (greater positive charge), yet the effect is to pull in the electron shells, making them smaller and screening outer electrons from the attractive force of the nucleus. More electron shells are added moving down a group, so the outermost electron becomes increasingly distance from the nucleus. (explains trend down)

increase in pressure

Goes from side with HIGHER # of moles to LOWER # of moles

decrease in pressure

Goes from side with LOWER # of moles to HIGHER # of moles.

Ionic solids characteristics

High melting points, high boiling points, and poor electrical conductivity in the solid state but high conductivity in the molten or aqueous state. electricity because IONS (NOT electrons) are free to move.brittle. low vapor pressure due to strong electrostatic interactions

chemical equilibrium

In a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of the reactants and products do not change with time. amts of p and r can be different at equilibrum

Are the strengths of the interactions between the particles in the solute and between the particles in the solvent before the solute and solvent are combined greater than, less than, or equal to the strengths of the interactions between solute particles and solvent particles after dissolution? Explain.

In an endothermic reaction, the strengths of the interactions between the solute particles and between the solvent particles are greater than the strength of the interactions between solute and solvent particles. or The strengths of the interactions between the solute particles and between the solvent particles are greater than the strength of the interactions between solute and solvent particles" (and the response further explains that the change in energy is equal to the sum of the energies required to separate solute particles from one another and solvent particles from one another minus the energy released when attractions between solute particles and solvent particles form).

ionic bond vs covalent bond

Ionic- transfer of electrons Covalent- sharing of electrons to become more stable

electrons are free to move through the substance=

It conducts electricity

temp always needs to be in

KELVIN!!!! DONT FORGET THIS one exception: q=mcdeltat. just pay attention to units lol

intermolecular forces weakest to strongest

LD, dipole-dipole, hydrogen bonding, and ion-dipole

The diagram above best illustrates which of the following phenomena associated with solids that have metallic bonding?

Malleability, because it shows how adjacent layers of positive ions can move relative to one another while remaining in full contact with the electron sea.

Hyrdogen Bonding rules and why is it so strong?

N,O,F. the small size of the hydrogen atom allows the approach of dipoles to be very close and the polarity of the bond are also why its so strong.

The complete photoelectron spectrum of an element is given above. Which labeled peak corresponds to the 1s electrons and why?

Peak X, because 1s electrons have the strongest attractions to the nucleus.

Analyte

Substance being analyzed. concentration is unknown

Two aqueous NaCl solutions of equal volume and concentration were kept in flasks and held at different temperatures. The two solutions were combined in a larger flask. Based on this information, which of the following predictions is correct?

The average kinetic energy of the particles in the cooler solution will increase as they collide with the particles from the warmer solution.

lewis structure central atom guidelines

The central atom is usually the least electronegative element in the molecule or ion;

The equilibrium reaction in 0.100M HBrO(aq) at equilibrium is represented by the equation above. Based on the magnitude of the equilibrium constant, which of the following correctly compares the equilibrium concentrations of substances involved in the reaction, and why? Keq=2.8×10−9

The equilibrium concentration of BrO−BrO− will be much smaller than the equilibrium concentration of HBrOHBrO, because Keq<1.

The particle diagrams above show the changes that occurred after an equimolecular mixture of X(g) and Y(g) was placed inside a rigid container at constant temperature. Which of the following statements is be best supported by the particle diagrams?

The forward reaction has a faster rate than the reverse reaction between 0sand 300s because more products were being formed.

How will the measured absorbance of the compound be affected if the student incorrectly orients the cuvette so that the path of the light is through the frosted sides of the cuvette?

The measured absorbance of the FeSCN2+ solution will be higher than the actual absorbance. Some of the light will be scattered/reflected by the frosted surfaces of the cuvette; thus less light will reach the detector in the spectrophotometer, making it appear as if the sample had absorbed more light.

lock and key model

The model of the enzyme that shows the substrate fitting perfectly into the active site

formal charge

The number of valence electrons in an isolated atom minus the number of electrons assigned to the atom in the Lewis structure. 1= bond 2=pair. want this to be 0.

The particle diagram above shows the system represented by the equation 2X(g)+Y2(g)⇄2XY(g) . Which of the following explains whether the particle diagram indicates that the system is at equilibrium?

The particle diagram does not indicate that the system is at equilibrium because it shows the system only at one point in time.

if a student analyzing the same concentration of this dye neglected to wipe fingerprints off the cuvette before placing it in the spectrophotometer, how would the absorption curve be affected?

The peak of the curve would be higher because more light would be absorbed. (causes the light to scatter resulting in less light passing through the sample. This will result in less light being detected and the instrument thinking there is greater absorbance than is really the case.)

why is the tetrahedral arrangement polar

The two electronegative chlorine atoms create a partial negative charge on their side of the carbon atom, leaving a partial positive charge on the opposite (hydrogen) side of the carbon atom. This separation of charge constitutes a dipole, and the molecule is polar.

Which of the following best helps explain why the first ionization energy of K is less than that of Ca?

The valence electron of K experiences a lower effective nuclear charge than the valence electrons of Ca.

ionic solid

a crystalline solid held together by ionic bonds. type of bonding: ionic-dipole.

common ion effect

a decrease in the solubility of an ionic compound caused by the addition of a common ion (le chatelier)

lattice energy

a measure of the energy released when ions are combined to make a compound.

vapor pressure of a liquid

a measure of the force exerted by a gas above a liquid. this is when the system is at equilibrium.

interstitial alloy

a mixture formed when small atoms fill holes in a metallic crystal

molecular solid

a solid composed of molecules. held together by intermolecular forces (dipole-dipole and hydrogen bonding -polar and London dispersion-nonpolar)

number of electrons ejected depends on light intensity so long as the light is

above a min energy ( this is also the ionization energy for a metal)

electronegativity on the periodic table explained

across a period: If the valence shell of an atom is less than half full, it requires less energy to lose an electron than to gain one. Conversely, if the valence shell is more than half full, it is easier to pull an electron into the valence shell than to donate one. down a group: This is because atomic number increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius.

ur given activation energy and delta e for a reaction. what is the activation energy for the reverse reaction

activation energy - delta e. draw a picture and go backwards.

first step in hetergenous catalysis is

adsorption of reactant molecules onto mental surface, (active sites which are locations at which reactants attach to metal catalyst)

enthalpy of reaction

aka: heat of reaction. (products - reactants). kj/mol

colliding particles

also must be correctly oriented to one another in order to produce an reaction. bonds must be able to be broken as shown in picture (diagram 1)

change in temp to a system

always results in shifts in eq. and change in k

specific heat capacity vs molar

amount of heat to raise temp one g of substance 1 k. units: j / g c or k and amount of heat to raise temp one mole of substance 1 k. units: j/mol c or k

k for forward and reverse reaction

are reciprocals

for exothermic reactions

as t increases, shift left, k decreases as t decreases, shift right, k increase

for endothermic reactions

as t increases, shift right, k increase as t decreases, shift left, k decreases

explain a graph of covalent bonds

as the atoms approach each other, the energy decreases until the distance reaches a good point and then begins to increase again due to repulsions. The lowest potential energy on the curve corresponds to the most stable internuclear distance

when is k (equilibrium) constant

at any temp

Maxwell-Boltzmann distribution

at higher temps, a larger population of molecules has higher energy. all have the same integral . Maxwell-Boltzmann

ion-dipole forces

attractive forces between an ion and a polar molecule

why is heat of formation zero for any element in its standard state

because it takes no energy to form a naturally-occurring compound

why does daltons law of partial pressure work

because pressure only depends on the total amount of gas when volume and temperature are held constant.

why is liquid to solid exothermic

because the change is one where the matter loses heat

why is n2 not polar

because the three bonding pairs of electrons are shared equally between the two N atoms, and each N atom has a nonbonding electron pair.

why does Methanol not ionize in water?

being a molecular compound, does not ionize in water and will not form aqueous solutions that conduct electricity. has to ionize to conduct electricity

Examples of endothermic reactions

boiling, melting, sublimation (s to g)

how to find delta h through bond enthalpies

bond enthalpies of bonds broken - bond enthalpies of bonds formed. since required energy to form and then energy released, you can see the change in energy and the direction of which the energy is going.

bond enthalpy vs enthalpies of formation (to find delta h)

bond enthalpy ( total energy required + energy released) heat of formation= (products - reactants)

if k<.01 (ice)

can ignore any -x in equation ( change value in concentrations)

how to find strongest ionic bonds

charge first / amount, then size

what doesn't change at equilibrum

concentration

rate constant k is not affected by

concentration but is affected by temp and catalysts

k doesnt depend on

concentration of reactants

what is determined by rates (equilibrium)

concentrations and activation energy

shifts to left means

consumes products and forms reactants until equilibrium is achieved

shifts to right means

consumes reactants and forms products until equilibrium is achieved

Electronegativity difference in bonding atoms = 0

covalent

ionization energy trend

decreases from top to bottom in a group; increases from left to right in a period

rate =

delta concentration / delta time. will be negative if reactant, postive if product.

change in energy of internal system

delta e = e final - e initial

at equilibrum

delta g = 0

integrated rate law

describes how concentration depends on time. for each type of integrated rate law, there is a differential rate law

sign tells u

direction of heat

retention factor (Rƒ)

distance travelled by sample/distance travelled by solvent

lower absorbance than actually is

distilled water

p-v changes

does not change k, as long as temp isnt change

potential energy is due to

electrostatic particles between charged particles. this is related to the specific arrangements of atoms in the substance.

enthalpy change (triangle H)

energy required (bonds broken) - energy released (bonds formed)

molar heat of fusion

energy required to melt 1 mole of a substance (heat of fusion is per gram). how to find this on a graph. point a-point b. point a= right before it turns into liquid. point b= right after it isn't completely a solid anymore

when time keeps going but the vapor pressure stabilizes

equilibrium, rate of condensation = rate of vaporization

collision model

explains how rate is affected by concentration and temp. greater concentration, more collisions per sec. higher temperature: faster particles, more collisions per sec, activation energy is exceeded more often

enthalpy

flow of heat in a reaction

form vs breaking bonds

form = exothermic break= endo

intermediate

formed then consumed shortly after

examples of exothermic reactions

freezing, condensation, deposition (deposition occurs when molecules settle out of a solution. Deposition can be viewed as a reverse process to dissolution)

Reduction means

gaining electrons

how to figure out order

given CONCENTRAION and intial rate, CONCENTRAION doubles, intial rate doubles = 1st, etc. INTIAL RATE DEPENDS ON CONCENTRAION

greater the ions/charges

greater electrostatic forces.ex: cacl2 vs nacl

smaller the ions

greater the attraction. ex: kbr vs lif

slowest step

has the highest activation energy

maxwell-bolztmann graph axis's

has to be kinetic energy (x axis) and fraction of molecules (y axis)

equilibrium concentrations don't

have to be equal, on k. unlimited combos for concentrations.

substitution alloys

he atoms of the original metal are literally replaced with atoms that have roughly the same size from another material. ex: brass

q

heat is entering system from surroundings

-q

heat is leaving system to surroundings

delta of h =

heat of formation (products) - heat of formation (reactants)

reaction coordinate diagram

high point of diagram: transition state species present at the transition state: activated complex energy gap between reactants and activated complex: activation energy barrier

real gases only behave ideally at

high temps and low pressure

vapor pressurs and temp

increases with temp

Electronegativity difference in bonding atoms = large

ionic

even though water is a liquid, adding water can cause a shift in equilibrium. why?

it dilutes aqueous components

why are metallic bonding good conductors

it's structure is a lattice of positive ions immersed in a sea of electrons

if you reverse reaction, k becomes (equilibrium)

k1

subsitute for k (usually)

k2k1 / k-1

Resonance bonds vs double bonds

longer and weaker

o2 graph vs n2 potential energy graph

look at bonds. -The curve has its minimum value to the right of where the given curve has its minimum value (because the length of the O-O double bond is greater than that of the N-N triple-bond) -The minimum value of the curve is higher than the minimum value of the given curve (because the energy of the O-O double bond is lower than that of the N-N triple-bond)

oxidized means

losing electrons

catalyst

lowers activation energy and is not consumed

metallic solid characteristics

malleability (able to be hammered/bent into a sheet), ductility (ability to be stretched into a wire) INSTEAD of brittle. melting points = high. conductor as a liquid and solid.

Law of Conservation of Energy tells us

mcdelta t= -mcdelta t -heat gained= heat lost

first order with respect to a and b products

means each reactant is 1st, overall is 2nd

metallic solid

metallic atoms, only has metals. type of bonds: metallic bonding/delocalized covalent.

molar heat capacity (formula)

molar mass times specific heat

how to find molar solubility

molar solubility represents x in an ice problem

4 types of solids

molecular, ionic, metallic, network covalent

k depends on

nature of reactants (state of matter, surface area,etc), temp, and order. order affects units, if catalyst is used.

network covalent

nonmetal atoms. type of bonds: covalent bonding (intra and inter are covalent)/directional covalent (leading to giant molecules). only 4 types: diamond, graphite, silicon dioxide (SiO2), silicon, sic

intramolecular forces straight lowest to highest

nonpolar covalent, polar covalent, ionic, and metallic. intramolecular forces aka bonds

increase in temp, increase in rate is

not a direct relationship, it is exponential

delta h for reverse reaction

opposite of reaction

vapor pressure of liquid in barometer

p vapor = p atmosphere - p Hh column

activated complex or transition state

peak

Electronegativity difference in bonding atoms = intermediate

polar covalent

produces CO2 and H2O. add o2

produces CO2 and H2O. add o2

If K>1

products are favored and equilibrium lies to the right

formula for changing states

q = +/- mcx (cx= heat of vaporization or heat of fusion)

formula for within a given state of matter

q= mc delta t

2nd step in hetergenous catalysis is

r bonds are broken or weakened, allowing p to form w a lower Ea, then, the products detach from catalysts

temp affects

rate

Catalysts and Rate

rate increases until the active sites of catalyst are filled. then the rate is independent of concentration

zero rate laws summary

rate law: rate =k integrated rate law: concentration of a = -kt + concentration of a at time = 0 straight line: concentration of a vs time relationship of rate constant to slope of straight line: slope = -k half life: t1/2 = concentration of A at time = 0 / 2k

rate laws vs equilibrium constant

rate laws- dont use coeffients for ^ (except in slow step in elementary reaction)

first order rate laws summary

rate= k(a) integrated rate law: ln(a) = -kt + ln (a) at t = 0kt= ln ( a0)/(at) straight line at: ln (a) vs t relationship of rate constant to slope of straight line: slope = -k half life: t1/2= .693 /k

second order rate laws summary

rate= k(a)^2 integrated rate law: 1/(a) = kt + 1/a(0 or at t = 0) kt= 1/(a)0 - 1/a(t) straight line at: 1/a (a) vs t relationship of rate constant to slope of straight line: slope = k half life: t1/2= 1 /(k times a at t = 0)

how mole ratios relate to rates

rates for reaction n2 + 3h2, n2 goes down 1/3 as fast as h2.

What is equal at equilibrium?

rates, concentration is not

thermal equilibrium

reached when the average kinetic energy of the particles from both solutions is the same. Thermal equilibrium will always occur at a temperature between the highest and the lowest temperature of the substances in contact. The average kinetic energy of the particles in the warmer solution is higher than the average kinetic energy of the particles in the cooler solution. Therefore, energy will be transferred from the particles in the warmer solution to the particles in the cooler solution via particle collisions.

if K<1

reactants are favored and equilibrium lies to left

If Q=K

reaction is at equilibrium

If Q>K

reaction shifts left. this means it has not reached equilibrium

If Q<K

reaction shifts right. As a system approaches towards equilibrium, Q approaches towards K.. Since Q<K, the reaction will shift to the right to reach equilibrium. visa versa. this means it has not reached equilibrium

how to know when to combine masses within calorimetry problems

reactions or solutions = add masses piece of metal into water = don't add masses

heating curve and heat

right to left: -q left to right: q on flat line use q= +/- mcx on increasing/decreasing line use q= mc delta t

Resonance bonds vs single bonds

shorter and stronger

sigma and pi bond rules

single bonds between atoms are always sigma bonds. Double bonds are comprised of one sigma and one pi bond. Triple bonds are comprised of one sigma bond and two pi bonds.

similar imfs =

soluble in each other

The diagram above shows thin-layer chromatograms of the same mixture of two compounds. Based on the chromatograms, which solvent would be most effective at separating the two compounds if the same stationary phase is used for column chromatography?

solvent c

catalysts

speed up reaction without being used up. appear as an reactant in elementary step and are produced as a product. can be in rate law. it introduces a different reaction path that reduces the activation energy.

Titrant

standard solution of known concentration

potential energy and bond strength

stronger or more stable the bond, the less potential energy there is between the bonded atoms. Strong bonds have low potential energy and weak bonds have high potential energy.

collisions must have

sufficient energy to produce the reaction (must equal or exceed activation energy).

Maxwell-Boltzmann distribution explained

temp = avg kinetic energy. more molecules in lower temp will have low kinetic energy, more molecules with higher temp will have higher kinetic values. this explains height differences.

Equilibrium constants are changed if you change the

temp of the system

Ionic bonding and covalent bonding will always be stronger

than intermolecular forces in any given substance

electronegativity trend

the ability of an atom to attract electrons when the atom is in a compound. increases to the right, decreases down

molar heat of vaporization

the amount of heat absorbed by one mole of a liquid as it vaporizes at a constant temperature

bond enthalpy

the energy needed to break one mole of bonds in gaseous molecules under standard conditions. endothermic process

bond energy

the energy required to break a chemical bond. endothermic process.

enthalpy of formation

the enthalpy change for a reaction in which one mole of a compound is formed from its elements in their standard states

solvent front

the furthest point reached by the solvent.

given graph of energy and reaction coordinate, where is the overall activation energy for the reaction

the highest bump/ the highest activation energy. (only strong as ur weakest player)

heat capacity

the number of heat needed to raise the temperature.

boiling point

the temperature at which its vapor pressure is equal to the pressure of the gas above it (usually the pressure of the atmosphere)

Which of the following best explains whether or not the particle diagram can predict the relative value of the enthalpy change for the dissolution of CuCl(s)?

the value of the enthalpy change for the dissolution of CuCl(s)CuCl(s) cannot be predicted from the particle diagram because it fails to illustrate the amount of energy required to overcome the forces between solute particles and between solvent particles.

Describe how to use the information from the mass spectrum to determine the average atomic mass of the element.

the weighted average must be calculated by finding the sum of three terms, each of which is the product of the proportional abundance of each isotope and the mass of each isotope

reaction have three steps

three bumps

decrease in concentration can be sometimes done

through making a solid (precipitate) or liquid (water)

where are indemediates on graph

valleys

vapor pressure, boiling point, and freezing points and intermolecular forces relationship

vapor pressure: The stronger the intermolecular forces, the lower the vapor pressure freezing point: Molecules with stronger intermolecular forces are pulled together tightly to form a solid at higher temperatures, so their freezing point is higher. Molecules with lower intermolecular forces will not solidify until the temperature is lowered further. boiling point: substances with stronger bonds will have a higher boiling point.

Enzyme

very large protein molecules. biological catalysts. very specific, for one reaction. names end in -"ase"

hybridization rules

when an atom is surrounded by 3 effective pairs: sp2 4:sp3 5:dsp3 6:d2sp3

reaction: a + b -----> C. give two ways rate law could be zero for a.

when concentrations of a don't change when initial rate changes. or when a isn't in the slowest elementary step.

what does product favored mean

when equilibrium is achieved, most reactant has been converted to product

what does reactant favored mean

when equilibrium is achieved, very little reactant has been converted to product

titration

when equivalence point is reached when just enough titrant is added to react with all of the analyte. may be indicated by a color change. when moles of acid = moles of base basically

how to find strongest hydrogen bonding

which has more h -bonds

how to find strongest dipole-dipole

which is more polar?

how to find strongest LDF

which one has biggest radius/mass(more polarizable)