For which reaction $\Delta H \neq \Delta U ?$

At $298 \mathrm{~K}, \Delta_r U^{\ominus}$ and $\Delta_r S^{\ominus}$ for the following reaction are -10.5 kJ and $+44.1 \mathrm{JK}^{-1} ; 2 X(\mathrm{~g})+Y(\mathrm{~g}) \longrightarrow 2 Z(\mathrm{~g})$ What is $\Delta_r G^{\ominus}$ (in kJ ) for this reaction? $\left(R=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\right)$

Consider the following gaseous equilibrium reactions (I), (II) and (III) with equilibrium constants $K_1, K_2$ and $K_3$ respectively

(I) $\frac{1}{2} \mathrm{~N}_2+\frac{3}{2} \mathrm{H}_2 \rightleftharpoons \mathrm{NH}_3$

(II) $2 \mathrm{NO} \rightleftharpoons \mathrm{N}_2+\mathrm{O}_2$

(III) $\mathrm{H}_2+\frac{1}{2} \mathrm{O}_2 \rightleftharpoons \mathrm{H}_2 \mathrm{O}$

The correct expression for the equilibrium constant for the gaseous equilibrium reaction

$$ 2 \mathrm{NH}_3+\frac{5}{2} \mathrm{O}_2 \rightleftharpoons 2 \mathrm{NO}+3 \mathrm{H}_2 \mathrm{O} \text { is } $$