The number of molecules with energy greater than the threshold energy for a reaction increases five fold by a rise of temperature from 27 °C to 42…

The number of molecules with energy greater than the threshold energy for a reaction increases five fold by a rise of temperature from $\displaystyle 27$ °C to $\displaystyle 42$ °C. Its energy of activation in $\displaystyle \mathrm{J} / \mathrm{mol}$ is \_\_\_\_. (Take $\displaystyle \ln 5=1.6094$; $\displaystyle \mathrm{R}=8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ )