# Consider the following reaction :

Question:

Consider the following reaction :

$\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{~g}) ; \Delta \mathrm{H}^{0}=+58 \mathrm{~kJ}$

For each of the following cases ((i), (ii)), the direction in which the equilibrium shifts is :

(i) Temperature is decreases

(ii) Pressure is increased by adding $\mathrm{N}_{2}$ at constant $\mathrm{T}$.

1. (i) towards product, (ii) towards product

2. (i) towards reactant, (ii) towards product

3. (i) towards reactant, (ii) no change

4. (i) towards product, (ii) no change

Correct Option: , 3

Solution:

(i) As reaction is endothermic $(\Delta \mathrm{Hz}=+\mathrm{ve})$ so on decrease in temperature equilibrium will shift towards reactant side.

(ii) On increase in pressure by adding inert gas $\left(\mathrm{N}_{2}\right)$ at same temperature, no shifting will take place. The equilibrium changes only if the added gas is a reactant or product involved in the reaction.