question

also called the equilibrium expression; law that says that the concentrations of all the products multiplied together divided by those of the reactants will be equal to the equilibrium constant K

answer

law of mass action

question

value of the equilibrium constant depends on _ _ _ _ and _ _ _ _

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specific reaction, temperature of the reactants at equilibrium

question

equilibrium constant for the partial pressures of gases

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K(p)

question

equilibrium constant for solubility product

answer

K(sp)

question

equilibrium constant for formation constant of complexities

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K(f)

question

equilibrium constant for dissociation constant in complexation reactions

answer

K(d)

question

all substances with ___ ___, such as __ __ __, are not part of the equilibrium expression

answer

constant concentration, pure liquids/solids

question

when adding chemical reactions, K(overall) equals _ _ _

answer

K(1) x K(2)

question

purpose of equilibrium constant

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to determine the extent to which reactants are converted into products

question

if K is less than ___, no visible reaction occurs

answer

10^-10

question

spontaneous reactions have equilibrium constants __ __ __

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greater than 1.00

question

nonspontaneous reactions have equilibrium constants __ __ __

answer

less than 1.00

question

number obtained by entering all the required concentrations into the equilibium expressions and calculating the result (not at equilibrium)

answer

reaction quotient "Q"

question

if QK(c), the reaction will move in the ____ direction

answer

forward, reverse

question

given equation for K(p)

answer

K(p)=K(c) x (RT)^Δn(g)

question

if the value of an equilibrium constant is given without speciying K(p) or K(c), you can assume that it is ___ the chemical equation requires one or more substances in solution

answer

K(p)

question

a decrease in the solubility of a compound when it is dissolved in a soution that already contains an ion in common with the salt being dissolved

answer

common ion effect

question

metal ions react with anions and molecules to form this

answer

complexes

question

equilibrium constant when the reactants come together to form a complex ion

answer

formation constant

question

equilibrium constant when the complex ions reactant breaks apart into products

answer

dissociation constant

question

whenever a system in dynamic equilibrium is disrupted by changes in chemical concentrations or physical conditions, the system will respond with internal physical and chemical changes to reestablish a new equilibrium, if possible

answer

Le Chartelier's Principle

question

increasing the pressure of a gaseous reaction system by decreasing its volume will have an effect on the equilibrium only if _______________

answer

Δn(g) is not zero

question

increasing the pressure on gaseous reactants favors the ______, while decreasing favors the ______

answer

reactants, products

question

the only experimental variable that has any effect on the value of the equilibrium constant is ____

answer

temperature

question

temp increases, reaction exothermic, favors ___

answer

reactants

question

temp increases, reaction endothermic, favors ___

answer

products

question

temp decreases, reaction exothermic, favors ___

answer

products

question

temp decreases, reaction endothermic, favors ___

answer

reactants

question

unit of reaction rates

answer

mol/Ls

question

another name for concentration vs time curve

answer

kinetic cruve

question

slope = -rate(reactants) = rate(products) = this

answer

-ΔC/Δt

question

4 factors that affect reaction rates

answer

concetration, temperature, ability to meet (phase), catalyst present

question

T/F: catalysts always appear in the balanced equation

answer

false, they never do

question

rate law equation

answer

rate = k * [A]^x * [B]^y * [C]^z

question

T/F: there is no theroretical way to predict the exponents of a rate law

answer

true

question

the order of the reaction indicatesthis

answer

exponents of the rate law

question

T/F: you can be first order in respect to one reactant and second order overall

answer

true

question

unit of the rate constant of the rate law

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(mol/Ls) / (mol/L)^order

question

Arrhenius equation; one way is k = A*e^(-E(a)/RT)

answer

ln(k) = -E(a)/RT + ln(A) where E(a) is activation energy, R=8.314J/(mol*K), temp is in K, A is the proportionality constant

question

Arrhenius plot has the x axis ___, the y axis __ and the slope ___

answer

1/T, ln(k), -E(a)/R

question

to compare two rates, ln( rate(1)/rate(2) )

answer

-E(a)/R * ( 1/T(1) - 1/T(2) )

question

two principles to check the reasonableness of Arrhenius equation-generated answers

answer

larger rate will always be the higher temp, activation energy is always positive

question

zero order reaction means rate _ _ _ _ _, y axis of a _ _, a slope of _, an integrated rate equation of _ _, and half-life of _ _

answer

does not depend on the concentration of any reactant, [A], -k, [A] = [A(0)] - kt, [A(0)] / 2k

question

first order reaction has y axis of a _ _, a slope of _, an integrated rate equation of _ _, and half-life of _ _

answer

ln[A(0)], -k, ln( [A(0)]/[A] ), 0.693/k

question

second order for [A(0)]^2 has axis of a _ _, a slope of _, an integrated rate equation of _ _, and half-life of _ _

answer

1/[A], k, 1/[A] - 1/[A(0)] = kt, 1/k[A(0)]

question

reaction rate is equal to the frequency of the effective collisions between reactants

answer

collision theory

question

for collisions to be effective, _ _ _ _ _

answer

molecules collide with sufficient energy and in proper orientation so products form

question

fraction of all collisions that have the miniumum energy needed for reactions can be calculated using _ _ _

answer

kinetic molecular theory (of gases)

question

reaction rate using collision theory

answer

N*f(e)*f(o) = (number of collisions per sec)(fraction with minimum energy)(fraction with correct orientation)

question

number of collisions per sec depends on _ and _

answer

temperature, concentration of reactants

question

T/F: f(e) and f(o) both increase as temp increases

answer

fasle, just f(e)

question

describes the molecular configurations and energies as a collisions occur, recognizing that proximity distorts molecules, weakening bonds within molecules so they break and new ones form

answer

transition-state theory

question

state represented in this ex: as Cl and HI approach, H-I bond weakens and H-Cl bond strengthens until the former is half broken and the latter half formed (upon recoiling the state breaks apart)

answer

activated complex

question

also called potential energy diagram, it shows the energies of reactants during collisions

answer

reaction profile

question

reaction profile has a y axis of _ _ _ and an x axis of _ _ _ (helps detemine heat of reaction and E(a) of reverse reactions)

answer

potential energy (as KE decreases, PE increases), reaction coordinate (location?)

question

rate constant is _ related to activation energy

answer

inversely

question

complete sequence of steps in a reaction

answer

reaction mechanism

question

series of smaller steps in a reaction usually involving one molecule breaking apart or two reactants colliding

answer

elementary reactions

question

in elementary reactions, the exponents of the rate law are _ _ _ _

answer

coefficients in the balanced equation

question

also called the rate-limiting step, this is the slowest state that determines the overall rate of the reaction

answer

rate-determining step

question

any chemical species that is part of a mechanism but not part of the balanced equation

answer

imtermediate

question

if the second state is the rate-determining step, the first reaction must be relatively fast and reversible, meaning the formation of the intermediate is equal to its disappearance and the forward rate in the orginial rate equation equals the reverse rate of this intermediate reactant (PR pg 414)

answer

steady-state assumpion

question

where there is no transfer of energy or matter to or from the surroundings

answer

isolated system

question

where energy can be transfered to the surrounds but matter cannot

answer

closed system

question

describe an aspect of a chemical system (like pressure, temp, volume, number of atoms/molecules) and depend on the change in a function, not initial numbers (ex: 15 to 4 = 125 to 114)

answer

state functions

question

two non-state functions are _ and _ as they depend on the sequence of events used to transform matter from the initial state ot the final state

answer

heat (q), work (w)

question

___ properties are qualities that change as the amount of the sample changes

answer

extensive

question

internal energy, enthalpy, entrophy, Gibbs free energy are all ___ properties

answer

extensive

question

to make extensive properties intensive, we must define precisely _, _, _, and _ _

answer

temp, pressure, mass, physical state

question

exo- means energy _; endo- means energy _

answer

lost, gained

question

equation for KE

answer

.5mv^2

question

gravitation energy (PE) has an equation of _ while electrostatic attraction (PE) is _

answer

m(1)m(2)/r, q(1)q(2)/r

question

energy needed to raise 1 gram of a substance 1 degree C

answer

specific heat

question

specific heat of water

answer

1 cal/gC or 4.184 J/gC

question

specific heat x molar mass is about equal to 25/molC

answer

Dulong and Petit Law

question

first law of thermodynamics can define energy using the equation

answer

ΔE = q + t

question

equation for work

answer

force x distance = pressure x area x distance = pressure x Δvolume

question

q(p) meaning

answer

heat with constant pressure

question

q(v) meaning

answer

heat with constant volume

question

calorimeter that does not allow volume to change, making ΔE zero

answer

bomb calorimeter

question

H; heat content of a substance

answer

enthalpy

question

relationship between energy and enthalpy

answer

ΔE = ΔH -PΔV

question

meaning of ΔH°, which has units of _

answer

standard heat of a reaction, kJ

question

meaning of ΔH(f)°, which has units of _

answer

standard heat of formation, kJ/mol

question

whenever mathematical operations are performed on a chemical equation, the same mathematical operations are applied also to the heat of reaction (like multiplying by constants or adding equations)

answer

Hess' law

question

requirements of a formation reaction

answer

reactants are elements in their standard states at 25C and 1 atm, and there is 1 mole of product

question

related to the number of different wars in which a system can arrange the particles within it

answer

entropy

question

entropy has a symbol of _ and units of _ while standard entropy has units of _

answer

S, JC, JC/mol

question

T/F: for elements, the standard heat of formation, standard entropy values and standard free energy are all zero

answer

false, this does not apply to S°

question

Boltzmann entropy equation

answer

S = k*ln(w) where k is the Boltzmann constant and w is the number of microstates

question

equation for standard entropy

answer

S°=q(rev)/T

question

process that occurs in infinitesimally small steps from initial to final state

answer

reversible process

question

T/F: the greater the position value of Δn(g), the greater the entropy

answer

true

question

ΔG°; maximum amount of energy available from any chemical reaction

answer

free-energy change

question

equation for Gibb's free energy

answer

ΔG° = ΔH° - TΔS°

question

if ΔG° is ____, the reaction is always spontaneous

answer

negative

question

equation for Gibb's free energy not in standard state

answer

ΔG = ΔG° + R*T*ln(Q)

question

equation for Gibb's free energy in standard state

answer

ΔG° = -R*T*ln(K)

question

diagram for ΔG°

answer

PR pg 442

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