For the reaction in equilibrium $ \mathrm{N}_{2(g)}+3 \mathrm{H}_{2(g)} \rightleftharpoons 2 \mathrm

Question

For the reaction in equilibrium $ \mathrm{N}_{2(g)}+3 \mathrm{H}_{2(g)} \rightleftharpoons 2 \mathrm{NH}_{3(g)}, \Delta H=-Q $ Reaction is favoured in forward direction by

Professor PC Thomas Classes · Answer

(d) : According to Le Chatelier's principle : (i) Raising the temperature shifts the equilibrium to left and decreases the equilibrium concentration of ammonia. In other words, low temperature is favourable for high yield of ammonia, but practically very low temperatures slow down the reaction and thus a catalyst is used. (ii) If $\mathrm{H}_2$ is added to the reaction mixture at equilibrium, then the equilibrium of the reaction is disturbed. In order to restore it, the reaction proceeds in a direction wherein $\mathrm{H}_2$ is consumed, i.e., more of $\mathrm{H}_2$ and $\mathrm{N}_2$ react to form $\mathrm{NH}_3$ and finally the equilibrium shifts in right (forward) direction. (iii) As the pressure increases, the equilibrium shifts in the forward direction, a direction in which the number of moles of the gas decreases.