Pre-exponential factors of two different reactions of same order are identical. Let activation energy of first reaction exceeds the activation energy of second reaction by \( 20 \, \text{kJ mol}^{-1} \). If \( k_1 \) and \( k_2 \) are the rate constants of first and second reaction respectively at \( 300 \, \text{K} \), then \( \ln \frac{k_2}{k_1} \) will be _________________.
(Nearest integer) \( \big[ \, R = 8.3 \, \text{J K}^{-1} \text{mol}^{-1} \, \big] \)