Question

N2 (g) + 3 H2 (g) ? 2NH3 (g) ?H = -92 kJ/mol a. Is this reaction exothermic or endothermic? b. What direction will the equilibrium shift if nitrogen gas is removed? c. What direction will the equilibrium shift if the temperature is lowered? d. What direction will the equilibrium shift if ammonia (NH3) is added? e. What principle helped you answer B-D?

Answer 1

Answer:- A) Exothermic, B) Reactant side(left side), C) Product side(right side), D) Reactant side(left side) and E) Le-chatelier's principle.

Explanations:- A) $\Delta H$ of the reaction is negative and it indicates an exothermic reaction.

B) Equilibrium shifts to the reactant side if nitrogen gas is removed. If anything is added then reaction moves in a direction where this added component is used and if something is removed then reaction moves in a direction where this removed component is formed.

C) Exothermic reactions are favored at low temperature and endothermic reactions are favored at high temperature. The temperature is lowered, so the reaction will shift to the product side.

D) The reaction shifts to the reactant side if ammonia is added so that it could be used to reestablish the equilibrium.

E) Le-chatelier's principle helps to answer B-D. As per this principle, reaction shifts in a direction where the stress is relieved. It means if anything is added then it must be used and if something is removed then it must be formed.