Chapter 14: Chemical Equilibrium Flashcards Preview

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Flashcards in Chapter 14: Chemical Equilibrium Deck (45):
1

equilibrium is a state of ... between ..

balance; opposing processes

2

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

products to form reactants

3

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

re-from the reactants

4

when a reaction is at equilibrium, it has not

stopped

5

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

dynamic

6

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

the same

7

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

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

8

for a given reaction, Keq is a ...

constant at any particular temperature

9

large values for K signify the reaction is

product favored

10

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

converted to product

11

small values for K signify the reaction is

reactant favored

12

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

converted to product

13

the equilibrium expression for a reverse reaction is the

reciprocal

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 ...

raised to the nth power

15

Kp=

Kc(RT)^Δn

16

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

the total number of moles of gas on the reactant side

17

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

systems not yet at equilibrium

18

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

current concentrations

19

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

direction

20

the concentrations of products and reactants change to bring Q

closer in value to Keq

21

if Q is less than Keq, the reaction proceeds

toward products

22

If Q > Keq, the reaction proceeds to

form reactants

23

At equilibrium,

Q = Keq

24

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

change; relieve that stress

25

lechatelier's principle: the system undergoes a ... in order to ...

temporary shift; restore equilibrium

26

lechatelier's principle can be exploited to

increase the yield of a reaction

27

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

producing additional products

28

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

composition

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

no effect

30

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

Keq

31

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

decreases; reactants; increases; products

32

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

change

33

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

included in the expression for the equilibrium constant

34

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

described by the law of mass action

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

products from reactants

36

solubility equilibria: reactions that involve the

dissolution and formation of a solid from solution

37

... are used to describe solubility equilibria

net ionic equations

38

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

solubility constant; chemical equation

39

the solubility product is the equilibrium constant that describes a

solid dissolving to produce ions in solution

40

solubility depends on both ... and the ...

Ksp; stoichiometry

41

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

contains an ion in common

42

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

ion in common with the substance

43

in a precipitation reation, the common ion effect predicts ...

decreased solubility of a precipitate

44

When Q exceeds Ksp, a ... will form

preciptate

45

If Q is less than Ksp, then more solid can

dissolve