The equilibrium concentrations of the species in the reaction $\mathrm{A}+\mathrm{B} \rightleftharpoons \mathrm{C}+\mathrm{D}$ are $2,3,10$ and $6 \mathrm{~mol}$ $\mathrm{L}^{-1}$, respectively at $300 \mathrm{~K} . \Delta \mathrm{G}^{0}$ for the reaction is $(\mathrm{R}=2 \mathrm{cal} / \mathrm{mol} ~\mathrm{K})$