Question

The following question refers to the reaction:

4NH3(g) + 5O2(g) ⇌ 4NO(g) + 6H2O(g)

The reaction as written is exothermic. What will happen if heat is added to the system?

(A) The equilibrium will shift to the left

(B) The equilibrium will shift to the right

(C) The NO concentration will remain constant, but there will be more water vapour

(D) The equilibrium position will not change if heat is added

(E) The system increase in temperature

Explanation will be much appreciated! Thanks in Advance

Answer 1

According to Le Chatelier principle, a system at equilibrium when disturbed by an external force will proceed in an opposite direction to negate the external force.

So when heat is added to the system at equilibrium, the reaction proceeds in a direction in which added heat is consumed.

Given the reaction as written is exothermic. So the backward reaction would be endothermic. Hence by adding heat backward reaction will take place to absorb the extra heat added.

Ans: (A) The equilibrium will shift to the left