d
Any change in the concentration, pressure and temperature of the reaction results in change in the direction of

equilibrium. This change in the direction of equilibrium is governed by Le-Chatelier's principle. According to Le-Chatellier's principle, equilibrium shifts in die opposite direction to undo the change. \(\mathrm{N}_{2}(\mathrm{g})+3 \mathrm{H}_{2}(\mathrm{g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{g})+\mathrm{Heat}\)

(a) Increasing the concentration of \(N H_{3}(g):\) On increasing the concentration of \(N H_{3}(g)\). the equilibrium shifts in the backward direction where concentration of \(N H_{3}(g)\) decreases

(b) Decreasing the pressure: since, \(p \propto n\) (number of moles), therefore, equilibrium shifts in the backward direction where number of moles are increasing.

(c) Decreasing the concentration of \(N_{2}(g)\) and \(H_{2}(g)\) Equilibrium shifts in the backward direction when concentration of \(H_{2}(g)\) and \(H_{2}(g)\) decreases.

(d) Increasing pressure and decreasing temperature: On increasing pressure, equilibrium shifts in the forward direction where number of moles decreases. It is an example of exothermic reaction therefore decreasing temperature favours the forward direction