The following reaction is performed at $298\;K$ $2NO(g) +O_2(g) \to 2NO_2(g)$ . The standard free energy of formation of $NO(g)$ is $86.6\;kJ\; mol $ at $298\;K$. What is the standard free energy of formation of $ NO_2 (g) $ at $298\;K\; (K_p = 1.6 \times 10^{12})$