Chemical Equilibrium

Question 1

CO₂(g) + 3H₂(g) ⇌ CH₃OH(g) + H₂O(g)
State & explain what happens to the yield of methanol when the total pressure is increased.

Answer 1

• the yield increases
• as there are fewer moles on the right
• so equilibrium shifts to the right
• to oppose the increase in pressure

Question 2

CH₄(g) + H₂O(g) ⇌ CO(g) + 3H₂(g)
∆H = +206kJmol–1
State & explain what happens to the yield of hydrogen when temperature is increased.

Answer 2

• yield increases
• as the forward reaction is endothermic
• so equilibrium shifts to the right to oppose the increase in temperature

Question 3

State Le Chatelier’s principle.

Answer 3

if changes are made to a system in equilibrium, the position of equilibrium will shift to oppose the change

Question 4

State the meaning of a Hetereogeneous catalyst

Answer 4

different phase/state from reactants