Chemical Kinetics and Nuclear Chemistry

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 Jmol−1. If the pre-exponential factor of the forward reaction is 4 times that of the reversereaction, the absolute value of ΔG0 (in mol−1) for the reaction at 300K is____
(Given; ln(2)=0.7,RT=2500Jmol−1 at 300K and G in the Gibbs energy)