The %yield of ammonia as a function of time in the reaction $\mathrm{N}_{2}(g)+3\mathrm{H}_{2}(g) \rightleftharpoons 2\mathrm{NH}_{3}(g), \Delta \mathrm{H} T_{1}$, the %yield of ammonia as a function of time is represented by

JEE Advanced · 2015 · 24 May 2015 · Paper 1 · Equilibrium

The %yield of ammonia as a function of time in the reaction

N_{2} (g) + 3 H_{2} (g) ⇌ 2 NH_{3} (g), Δ H < 0

(P, T_{1})

is given below.
If this reaction is conducted at

(P, T_{2})

, with

T_{2} > T_{1}

, the %yield of ammonia as a function of time is represented by

Answer: (B)

The reaction is exothermic (

Δ H < 0

). According to Le Chatelier's principle:

At higher temperature ( $T_{2} > T_{1}$ ), the equilibrium shifts backward (favoring reactants), so the equilibrium yield decreases.
However, the rate of reaction increases at higher temperature, so equilibrium is reached faster.

Therefore, the curve should reach a lower equilibrium yield but in less time. This is represented by graph (B).

JEE Advanced · 2015 · 24 May 2015 · Paper 1 · One or more correct options