C5.3

Question 1

Dynamic equilibrium

Answer 1

Occurs when reversible reaction happens in closed system & rates of forward & backward reaction are equal

• concentration of all reacting substances remain constant

Question 2

Equilibrium position

Answer 2

Shows ratio of equilibrium concentrations of products to reactants

Question 3

What happens to equilibrium position when you change pressure

Answer 3

• pressure increase

- equilibrium position moves in direction of fewest moles of GAS

Question 4

What happens to equilibrium position if you change concentration

Answer 4

• concentration of a substance increase

- equilibrium position moves in direction away from that substance

Question 5

What happens to equilibrium position if you change temp

Answer 5

• temperature increased

- equilibrium position moves in direction of endothermic change

Question 6

Equilibrium yield

Answer 6

Amount of desired product present in reaction at equilibrium

Depends on

• pressure
• temp
• concentration of reactions

Question 7

La Chatelier’s principle

Answer 7

When a change is made to a reaction at equilibrium, position of equilibrium moves to oppose the change

Question 8

Compromise pressure

Answer 8

• high enough to achieve reasonable equilibrium yield

- low enough so it’s not expensive / hazardous

Question 9

Compromise temperature (if forward reaction exothermic)

Answer 9

• high enough to achieve reasonable rate of reaction

- low enough to achieve reasonable equilibrium yield