Two reactions $R_{1}and{R}_2$ have identical pre-exponential factors. Activation energy of $R_1$ exceeds that of $R_2$ by 10 $KJ mo{l}^{-1}.$ If $K_{\mathit{1}}\mathit{ }\mathrm{and}\mathit{ }{K}_{\mathit{2}}$ are the rate constants for $R_1\mathrm{and}{R}_2$ respectively at 300 K, then $\ln \left(\frac{K_2}{K_1}\right)is$ equal to: $(R=8.314J{K}^{-1}mo{l}^{-1})$