Consider the following reversible reaction, A(g) + B(g) ? AB(g). The activation energy of the backward reaction exceeds that of the forward reaction by 2RT (in J mol^-1). If the pre-exponential factor of the forward reaction is 4 times that of the reverse reaction, the absolute value of ?G? (in J mol^-1) for the reaction at 300 K is____.

Given; ln (2) = 0.7, RT = 2500 J mol–1 at 300 K and G is the Gibbs energy)