Equilibria and Kc

Question 1

What are the conditions of equilibrium?

Answer 1

• must occur in a closed system (products/reactants can’t escape)
• equilibrium can be approached from either direction and final position will be the same.
• dynamic is a dynamic process, reached when the rates of two opposing processes occurring at the same time are the same

Question 2

What is Le Châtelier’s principle?

Answer 2

If a system at equilibrium is disturbed, the equilibrium will shift in the direction that tends to reduce the disturbance.

Question 3

What is the effect of a catalyst on equilibrium?

Answer 3

Catalysts do not have the ability to shift equilibrium , they reduce the time taken to reach equilibrium by providing an alternative reaction pathway with a lower activation energy.

Question 4

What is Kc?

Answer 4

The equilibrium constant

Question 5

What is the effect of changing temperature on Kc?

Answer 5

Endothermic - increase = Kc increases
Endothermic - decrease = Kc decreases
Exothermic - increase = Kc decreases
Exothermic - decrease = Kc increases