Topic 10: Equilibrium I

Question 1

What is dynamic equilibrium?-

Answer 1

• when the rate of the forward reaction is equal to the rate of the backward reaction
• the concentrations of reactants and products remain constant

Question 2

What is a homogeneous system?

Answer 2

• a system in which everything is in the same physical state
• for homogeneous equilibria, all products and reactants are included in the expression for Kc

Question 3

What is a heterogeneous system?

Answer 3

• when everything is not in the same physical state

- you don’t include solids or pure liquids in the expression for Jc because their concentrations stay constant

Question 4

Do catalysts affect the equilibrium constant?

Answer 4

• catalysts aren’t included in Kc expressions
• they don’t affect equilibrium concentrations of the products or reactants
• they only speed up the rate at which the dynamic equilibrium is reached

Question 5

What is Le Chatelier’s Principle?

Answer 5

• If there is a change in concentration, pressure or temperature, the equilibrium will move to help counteract the change

Question 6

Using Le Chatalier’s Principle explain what would happen if you increased concentration and pressure of the reactant

Answer 6

• equilibrium shifts to the right

- etc etc you should know

Question 7

What happens when an exothermic reaction increases temp and therefore vice versa

Answer 7

• equilibrium shifts to the left in the endothermic direction to absorb this heat