Question

For this reaction relate $\Delta H$ and $\Delta U$
$2N{O}_2\left(g\right)⟶N_2{O}_4\left(g\right)$

• A. $\Delta H$ =$\Delta U$
• B. $\Delta H$ > $\Delta U$
• C. $\Delta H$ < $\Delta U$
• D. None of these

Answer 1

The correct option is C $\Delta H$ < $\Delta U$

As we know,
$\Delta H$ =$\Delta U+\Delta n_{g}RT$
here,
$2N{O}_2\left(g\right)⟶N_2{O}_4\left(g\right)$
$\Delta n_g=-1$
so,
$\Delta H$ < $\Delta U$