3H2 (g) + N2 (g) ⇔ 2NH3(g) ΔH – 49.95 KTmol−¹
Describe, according to Le Chatelier’s Principle how the equilibrium in the above equation will vary when:
i. More hydrogen is added.
ii. Ammonia is removed
iii. The pressure is increase
iv. The temperature is decreased
Solution
i. The hydrogen added will react with the nitrogen to produce more of ammonia – this equilibrium position shifts to the right.
ii. The hydrogen and nitrogen present will react to replace the removed ammonia – this shits the equilibrium position to the right
iii. The hydrogen and nitrogen with 4 gaseous volume will react to produce ammonia with 2 gaseous volumes, this equilibrium position shifts to the right.
iv. The temperature is decreased: The production of ammonia is exothermic while it’s decomposition is endothermic. A decrease in temperature favours the exothermic process. Thus hydrogen and nitrogen combine to produce more ammonia shifting equilibrium position to the right.
