Chapter 19 - Equilibrium

Question 1

What is homogeneous equilibria?

Answer 1

Equilibrium species all have the same state which are gases or aqueous

Question 2

What is heterogeneous equilibria?

Answer 2

Equilibrium species have different states which can be solid, liquid or gas

Question 3

Which species are omitted from K_c expression?

Answer 3

Solid and liquid

Question 4

What can also be used instead of moles in the mole fractions of K_p expression?

Answer 4

Volumes

Question 5

How to calculate mole fraction?

Answer 5

Mole fraction x(A) = Number of moles of A ÷ total number of moles in gas mixture

Question 6

What must all the mole fractions total to?

Answer 6

One

Question 7

How to calculate partial pressure (p)?

Answer 7

Partial pressure (p) = mole fraction x total pressure (P)

Question 8

What must all the partial pressure total to?

Answer 8

Total pressure

Question 9

What is the only factor that can change the value of K?

Answer 9

Temperature

Question 10

What happens to K when temperature is increased (forwards reaction: exothermic)?

Answer 10

Decreases

Question 11

Explain the equilibrium shift when temperature is increased (forwards reaction: exothermic)

Answer 11

Equilibrium shifts to LEFT
(P) decreases
(R) increases
K decreases

Question 12

What happens to K when temperature is increased (forwards reaction: endothermic)?

Answer 12

Increases

Question 13

Explain the equilibrium shift when temperature is increased (forwards reaction: endothermic)

Answer 13

Equilibrium shifts to RIGHT
(P) increases
(R) decreases
K increases

Question 14

What is the effect of changing concentration on value of K?

Answer 14

No effect, however equilibrium shift still occurs to correct the system

Question 15

What happens to the ratio of K_c or K_p when concentration of REACTANT increases?

Answer 15

Ratio of equilibrium expression is LESS than K_c or K_p as K decreases

Question 16

What corrects the equilibrium constant when the concentration of reactant increases?

Answer 16

• Concentration of PRODUCT must INCREASE
• Concentration of reactant must decrease

Question 17

What happens to the ratio of K_c or K_p when concentration of PRODUCT increases?

Answer 17

Ratio of equilibrium expression is MORE than K_c or K_p as K increases

Question 18

What corrects the equilibrium constant when the concentration of product increases?

Answer 18

• Concentration of REACTANT must INCREASE
• Concentration of product must decrease

Question 19

What is the effect of changing pressure on the value of K?

Answer 19

No effect, however equilibrium shift still occurs to correct the system

Question 20

What will doubling the pressure do to the partial pressures and concentrations of the reactants and products?

Answer 20

Doubles them BOTH

Question 21

What is the effect of a pressure change on K when there is GREATER mol of PRODUCT?

Answer 21

Increases

Question 22

What corrects the equilibrium constant after pressure change when there is GREATER mol of PRODUCT?

Answer 22

Products decrease
Reactants increase
Equilibrium shifts to LEFT

Question 23

What is the effect of a pressure change on K when there is GREATER mol of REACTANT?

Answer 23

Decreases

Question 24

What corrects the equilibrium constant after pressure change when there is GREATER mol of REACTANT?

Answer 24

Products increase
Reactants decrease
Equilibrium shifts to RIGHT

Question 25

What is the effect of a catalyst on the value of K?

Answer 25

No effect as only rate is affected and not the equilibrium