Question

The equilibrium constant for the reaction : $A\left(g\right)+B\left(g\right)\rightleftharpoons C\left(g\right)+D\left(g\right)$ is $1\times {10}^{-2}$ at 298K and it is 2 at 373K. The chemical process resulting the formation of C and D is

• A. Exothermic
• B. Endothermic
• C. Unpredictable
• D. There is no relation between K and DH

Answer 1

The correct option is B

Endothermic

$log\frac{K_{eq-2}}{K_{eq-1}}=\frac{△H}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}];$

Where $T_1<T_2;R=8.315\times {10}^{-3}KJ.K^{-1}.mo{l}^{-1}$

$log\frac{2}{1\times {10}^{-2}}=\frac{△H}{2.303\times (8.315\times {10}^{-3})}[\frac{1}{298}-\frac{1}{373}]$

$△H=+69.296KJ.mo{l}^{-1}$

Since $△H$ is +ve, forward reaction is endothermic