A first order reaction is completed in at and in at . Calculate the activation energy of the…

A first order reaction is $50\%$ completed in $40\text{ minutes}$ at $300\text{ K}$ and in $20\text{ minutes}$ at $320\text{ K}$. Calculate the activation energy of the reaction. (Given: $\log 2 = 0\cdot3010$, $\log 4 = 0\cdot6021$, $R = 8\cdot314\text{ J K}^{-1}\text{mol}^{-1}$)