Equilibria

Question 1

Define dynamic equilibrium

Answer 1

At equilibrium the rate of the forward reaction equals the rate of the reverse reaction

Question 2

What are the conditions required?

Answer 2

• Reversible reaction
• Closed system

Question 3

Define a closed system

Answer 3

A system where no exchange of matter takes place

Question 4

Le Chatelier’s Principle

Answer 4

Equilibrium shifts to oppose changes in temperature, pressure or concentration.

Question 5

Increasing temperature on an exothermic reaction

Answer 5

* Increasing temperature will shift the equilibrium to the left
* It will favour the backwards reaction as it is endothermic
* Yield of products decreases

Question 6

Increasing temperature on an endothermic reaction

Answer 6

• Increasing temperature will shift the equilibrium to the right
• It will favour the forwards reaction as it is endothermic
• Yield of products increases

Question 7

Increasing pressure when reactants have fewer moles

Answer 7

* Increasing pressure will shift the equilibrium to the left
* It will favour the side that has fewer moles of gas
* Yield of products decreases.

Question 8

Increasing pressure when products have fewer moles

Answer 8

* Increasing pressure will shift the equilibrium to the right
* It will favour the side that has fewer moles of gas
* Yield of products increases

Question 9

Increasing pressure with an equal number of moles of gas on both sides

Answer 9

• No effect.
• Increasing the pressure will speed up both the forward and backwards reaction by the same amount