Question

A first order reaction is $50\%$ complete in 200 hrs at ${27}^{\circ }C$ and in 20 hrs at ${27}^{\circ }C$ in presence of catalyst. The decrease in activation energy caused by catalyst is nearly

• A. 5.7 kJ
• B. 7.5 kJ
• C. 6.7 kJ
• D. 7.6 kJ

Answer 1

The correct option is A 5.7 kJ

$log\frac{k_2}{k_1}=\frac{\Delta {ϵ}_a}{2.303RT}$
$1=\frac{\Delta \left({ϵ}_a\right)}{2.303\times 8.314\times 300}$
$\Delta {ϵ}_a=5.7kJ$