A catalyst decreases activation energy by 15Kcal and it is observed that rate of reaction in absence of catalyst at 400 K is same as rate of reaction in presence of catalyst at 300 K. The activation energy in absence of catalyst will be :

A catalyst decreases activation energy by 15Kcal and it is observed that rate of reaction in absence of catalyst at 400 K is same as rate of reaction in presence of catalyst at 300 K. The activation energy in absence of catalyst will be :

$$\begin{gathered} \frac{E}{R\times 400} \\ =\frac{E-15}{R\times 300} \\ \Rightarrow E=60\mathrm{kcal} \end{gathered}$$