Question

$N_2+3H_2\rightleftharpoons 2N{H}_3$
Which of the followings the correct statement if $N_2$ is added at equilibrium condition ?

• A. The equilibrium will shift to the forward direction because according to the second law of thermodynamics, the entropy must increase in the direction of spontaneous reaction
• B. The condition for the equilibrium is $G\left(N_2\right)+3G\left(H_2\right)=2G\left(N{H}_3\right)$ where, G is the Gibbs free energy per mole of the gaseous species measured at that partial pressure. The condition of equilibrium is unaffected by the use of catalyst,which increases the rate of both the forward and backward reactions to the same extent.
• C. The catalyst will increase the rate of forward reaction by $\alpha$ and the backward reaction by $\beta$
• D. Catalysts will not alter the rate of either of the reactions

Answer 1

The correct option is A The equilibrium will shift to the forward direction because according to the second law of thermodynamics, the entropy must increase in the direction of spontaneous reaction

$N_2+3H_2\rightleftharpoons 2{NH}_3$

If $N_2$ is added at equilibrium, the reaction shift forward direction because according to Lechatlier principle the equilibrium reaction always try to attain equilibrium from any disturbance. Here it regains equilibrium by shifting reaction forward (i.e. reducing $N_2$ concentration & increasing product concentration)

Here (b), (c), (d) options are not at all relavent to question.