Chem Chapter 14

Front 1

Chemical equilibrium

Back 1

Dynamic process in which concentrations of reactants and products remain constant over time

Front 2

Dynamic process in which concentrations of reactants and products remain constant over time

Back 2

Chemical equilibrium

Front 3

Dynamic equilibrium

Back 3

The state of a chemical reaction in which reactant and product concentrations do not change, but products and reactants are continually interconverting

Front 4

The state of a chemical reaction in which reactant and product concentrations do not change, but products and reactants are continually interconverting

Back 4

Dynamic equilibrium

Front 5

What happens with the rates at equilibrium

Back 5

Rate of forward reaction =rate of reverse reaction

Front 6

What is included in the equilibrium constant expression

Back 6

Gases and aqueous, not liquid or solid (make those equal to 1)

Front 7

Equilibrium constant expression

Back 7

Ratio of equilibrium concentrations or partial pressures of products and reactants, each term raised to a power equal to the coefficient of that substance in the balanced chemical equation

Front 8

Ratio of equilibrium concentrations or partial pressures of products and reactants, each term raised to a power equal to the coefficient of that substance in the balanced chemical equation

Back 8

Equilibrium constant expression

Front 9

Equilibrium constant

Back 9

Value of the ratio of concentration (or partial pressure) terms in the equilibrium constant expression at a specific temp

Front 10

Value of the ratio of concentration (or partial pressure) terms in the equilibrium constant expression at a specific temp

Back 10

Equilibrium constant

Front 11

Equilibrium constant equation

Back 11

K = [C]^c [D]^d / [A]^a [B]^b

Products / reactants

Front 12

If equilibrium constant is much greater than 1:

Back 12

Equilibrium lies to the right

Products dominate

Front 13

If equilibrium constant is much less than 1:

Back 13

Equilibrium lies to the left Reactants dominate

Front 14

If equilibrium constant is equal to 0:

Back 14

No reaction

Infinitely more reactants than products

Front 15

If equilibrium constant is equal to infinity:

Back 15

Irreversible reaction

Divide by # approaching zero

No way to shift an irreversible reaction

Ex) combustion

Front 16

Range of K where products and reactants are comparable

Back 16

10^-2 to 10^2

Front 17

Law of mass action

Back 17

The equilibrium constant expression at chemical equilibrium has a characteristic value at a given temp

Front 18

The equilibrium constant expression at chemical equilibrium has a characteristic value at a given temp

Back 18

Law of mass action

Front 19

Mass action expression

Back 19

Equivalent to equilibrium constant expression, but applied to reaction mixtures that may or may not be at equilibrium

Front 20

Equivalent to equilibrium constant expression, but applied to reaction mixtures that may or may not be at equilibrium

Back 20

Mass action expression

Front 21

What values do we use for K?

Back 21

Use equilibrium concentrations, not initial values

Front 22

Units for K

Back 22

None

Front 23

Difference between Kc and Kp

Back 23

Kc uses concentrations

KP uses units of partial pressure

Front 24

For Keq, what do you do if an equation has both gas and aqueous?

Back 24

Use pressures for gas and concentrations for aqueous

Front 25

If more ice is added to an ice-water mixture at equilibrium, how will the vapor pressure of the water react?

Back 25

Vapor pressure of water will remain the same

Front 26

Kp and Kc equation

Back 26

Kp = Kc(RT)^delta n

R is gas constant

T is temp (K)

Delta n is number moles of gaseous products - moles of gaseous reactants

Front 27

When will Kc and Kp be diff?

Back 27

If # moles is diff

If difference in moles is 0, the equation has RT^0 which does nothing

Front 28

K forward reaction vs K reverse reaction

Back 28

K forward = 1/K reverse

K reverse has reactants/products

Front 29

How can equilibrium constant be changed?

Back 29

Change coefficients

NOT if change initial concentration

Front 30

What happens to K if chemical equation is multiplied by a number

Back 30

Changes the exponents in K equation

Front 31

Combining K values

Back 31

If chemical equation add up, multiply K equations to find K equation of final chemical equation (cancel things if need be)

Front 32

Reaction quotient

Back 32

Q

concentrations are not necessarily equilibrium concentrations

Front 33

Q

Back 33

Reaction quotient

concentrations are not necessarily equilibrium concentrations

Front 34

Equation for Q

Back 34

Same as K just not equilibrium concentrations

Front 35

Q related to K

Back 35

Q < K reaction goes forward (right)

Q > K reaction goes reverse (left)

Q = K reaction at equilibrium

Front 36

Homogeneous equilibria

Back 36

Equilibria involving reactants and products in same phase

Front 37

Equilibria involving reactants and products in same phase

Back 37

Homogeneous equilibria

Front 38

Heterogeneous equilibria

Back 38

Equilibria involving reactants and products in more than 1 phase

Front 39

Equilibria involving reactants and products in more than 1 phase

Back 39

Heterogeneous equilibria

Front 40

What phases can be included in K

Back 40

Gas, not liquid or solid

Front 41

Le Chatlier's Principle

Back 41

Factors that will change the relative rates of forward/reverse reactions, or change the value of Q compared to K, will cause a shift in the position of equilibrium

Front 42

Factors that will change the relative rates of forward/reverse reactions, or change the value of Q compared to K, will cause a shift in the position of equilibrium

Back 42

Le Chatlier's Principle

Front 43

Removing products or adding reactants effect on shift in equilibrium

Back 43

Remove products = equation shift to right

Front 44

Effects of pressure/volume on Q/K

Back 44

Decreasing volume by a factor of 2 will increase partial pressure by a factor of 2

Plugging into Kp formula, if there are different moles of gas on each side, reaction will shift towards one with less moles of gas

Front 45

How does pressure affect equilibrium?

Back 45

Increase pressure shifts equilibrium toward side with fewer moles

Front 46

How does volume affect equilibrium?

Back 46

Increase volume shifts equilibrium toward side with more moles of gas

Front 47

Temperature effect on equilibrium

Back 47

Treat heat as a reactant or product

Increase temp adds heat to right side of equation (if exo), so reaction shifts left

Front 48

Which effect on equilibrium will change K?

Back 48

Changing temp

Front 49

How does a catalyst affect equilibrium systems?

Back 49

Systems reach equilibrium faster

No change in K or position of equilibrium