Chapter 14: Chemical Equilibrium

Question 1

equilibrium is a state of … between ..

Answer 1

balance; opposing processes

Question 2

equilibrium is a state in which the tendency of the reactants to form products is balanced by the tendency of the

Answer 2

products to form reactants

Question 3

reversible reactions: a chemical reaction in which the products can react to

Answer 3

re-from the reactants

Question 4

when a reaction is at equilibrium, it has not

Answer 4

stopped

Question 5

chemical equilibria are … systems, as opposed to static systems in which processes stop

Answer 5

dynamic

Question 6

the experimentally determined equilibrium concentrations at the end of each experiment are

Answer 6

the same

Question 7

law of mass action (equilibrium constant expression): jA + kB lC + mD:

Answer 7

Keq= [C]l[D]m/[A]j[B]k

Question 8

for a given reaction, Keq is a …

Answer 8

constant at any particular temperature

Question 9

large values for K signify the reaction is

Answer 9

product favored

Question 10

product favored: when equilibrium is achieved, most reactant has been

Answer 10

converted to product

Question 11

small values for K signify the reaction is

Answer 11

reactant favored

Question 12

reactant favored: when equilibrium is achieved, very little react has been

Answer 12

converted to product

Question 13

the equilibrium expression for a reverse reaction is the

Answer 13

reciprocal

Question 14

when the balanced equation for a reaction is multiplied by a factor n, the equilibrium expression for the new reaction is the original expression …

Answer 14

raised to the nth power

Question 15

Kp=

Answer 15

Kc(RT)^Δn

Question 16

Δn= total number of moles of gas on the product side-

Answer 16

the total number of moles of gas on the reactant side

Question 17

the law of mass action not only describes equilibrium systems, but provides important information about

Answer 17

systems not yet at equilibrium

Question 18

the reaction quotient, Q, has the same algebraic form as Keq, but uses … rather than equilibrium concentrations in the calculations

Answer 18

current concentrations

Question 19

Comparing Q to Keq enables us to predict the … in which a reaction will proceed to achieve equilibrium

Answer 19

direction

Question 20

the concentrations of products and reactants change to bring Q

Answer 20

closer in value to Keq

Question 21

if Q is less than Keq, the reaction proceeds

Answer 21

toward products

Question 22

If Q > Keq, the reaction proceeds to

Answer 22

form reactants

Question 23

At equilibrium,

Answer 23

Q = Keq

Question 24

lechatelier’s principle: when a system at equilibrium is placed under stress, the system will undergo a … in such a way as to …

Answer 24

change; relieve that stress

Question 25

lechatelier’s principle: the system undergoes a … in order to …

Answer 25

temporary shift; restore equilibrium

Question 26

lechatelier’s principle can be exploited to

Answer 26

increase the yield of a reaction

Question 27

if the products of a reaction can be removed from the reaction mixture, the system responds by

Answer 27

producing additional products

Question 28

shift in equilibrium involves a change in …, not Keq!

Answer 28

composition

Question 29

as long as these other substances do not react or affect the partial pressures of the reactants or products, the pressures of materials other than the reactants or products have .. on the equilibrium

Answer 29

no effect

Question 30

changing the temperature of a reaction changes the value of …, in the direction predicted b Le Chatelier’s principle

Answer 30

Keq

Question 31

increasing the temperature of an exothermic reaction … Keq, so more … form; increasing the temperature of an endothermic reaction … Keq, so more … form

Answer 31

decreases; reactants; increases; products

Question 32

the concentration of a solid or a pure liquid does not … during the course of a reaction

Answer 32

change

Question 33

therefore, the concentrations of solids and pure liquids are not ….

Answer 33

included in the expression for the equilibrium constant

Question 34

if any of the substances in the chemical equation is no longer present, the system is not at equilibrium and it cannot be

Answer 34

described by the law of mass action

Question 35

heterogenous equilibria are important to study because chemists often strive to make the product in a different phase than the reactants so that the separation of .. is easier

Answer 35

products from reactants

Question 36

solubility equilibria: reactions that involve the

Answer 36

dissolution and formation of a solid from solution

Question 37

… are used to describe solubility equilibria

Answer 37

net ionic equations

Question 38

the solubility of a solid can be calculated from the … and the … for the dissociation of the solid

Answer 38

solubility constant; chemical equation

Question 39

the solubility product is the equilibrium constant that describes a

Answer 39

solid dissolving to produce ions in solution

Question 40

solubility depends on both … and the …

Answer 40

Ksp; stoichiometry

Question 41

common ion effect: a term used to describe the effect of adding a solute to a solution that

Answer 41

contains an ion in common

Question 42

the solubility of a precipitate is lower in a solution that contains an

Answer 42

ion in common with the substance

Question 43

in a precipitation reation, the common ion effect predicts …

Answer 43

decreased solubility of a precipitate

Question 44

When Q exceeds Ksp, a … will form

Answer 44

preciptate

Question 45

If Q is less than Ksp, then more solid can

Answer 45

dissolve