Chemistry Question from JEE Main 2023 · 29 January, Shift 1

Consider the following reaction approaching equilibrium at $27^\circ \text{C}$ and $1 \, \text{atm}$ pressure:

$A + B \rightleftharpoons C + D$

$K_f = 10^3$, $K_r = 10^2$

The standard Gibbs energy change ($\Delta_r G^\circ$) at $27^\circ \text{C}$ is $(-)$ _____ $\text{kJ mol}^{-1}$ (Nearest integer).

(Given: $R = 8.3 \, \text{J K}^{-1} \, \text{mol}^{-1}$ and $\ln(10) = 2.3$)