Question

The $K_p$ for reaction $A+B\rightleftharpoons C+D$ is $1.34$ at ${60}^{o}C$ and $6.64$ at ${100}^{o}C$. Calculate $\Delta H^o$ for the reaction over this range of temperature.

Answer 1

$T_1={60}^{o}C=333K,T_2={100}^{o}C=373K$

$K_1=1.34,K_2=6.64$

$\because$ In $\frac{K_2}{K_1}=\frac{\Delta H}{R}[\frac{1}{T_1}-\frac{1}{T_2}]$

$\therefore$ In $\left(\frac{6.64}{1.34}\right)=\frac{\Delta H}{8.314}[\frac{1}{333}-\frac{1}{373}]$

$\therefore \Delta H^o=41.31kJ$