Equation used is
\(\log \left(\frac{k_2}{k_1}\right)=\frac{E_a}{2.303 R}\left(\frac{1}{T_1}-\frac{1}{T_2}\right)\)
Hence \(E_a\) can be calculated if value of rate constant \(k\) is known at two different temperatures \(T_1\) and \(\mathrm{T}_2\)
$\mathrm{R}=8.314\; \mathrm{JK}^{-1} \mathrm{mol}^{-1}$