NEET 2017 Chemistry, question 86.

The equilibrium constants of the following are :

$\mathrm{N_2 + 3H_2 \rightleftharpoons 2NH_3}$ $K_1$

$\mathrm{N_2 + O_2 \rightleftharpoons 2NO}$ $K_2$

$\mathrm{H_2 + \frac{1}{2}O_2 \to H_2O}$ $K_3$

The equilibrium constant (K) of the reaction :

$\mathrm{2NH_3 + \frac{5}{2}O_2 \overset{K}{\rightleftharpoons} 2NO + 3H_2O}$, will be :