For the reaction, $\mathrm{N}_{2_{(\mathrm{g})}}+3 \mathrm{H}_{2_{(\mathrm{g})}} \rightarrow 2…
For the reaction, $\mathrm{N}_{2_{(\mathrm{g})}}+3 \mathrm{H}_{2_{(\mathrm{g})}} \rightarrow 2 \mathrm{NH}_{3_{(\mathrm{g})}} \Delta \mathrm{H}$ is equal to
$\Delta \mathrm{U}+\mathrm{RT}$
$\Delta \mathrm{U}+2 \mathrm{RT}$
$\Delta \mathrm{U}-\mathrm{RT}$
$\Delta \mathrm{U}-2 \mathrm{RT}$
Solution
$\mathrm{N}_{2(\boldsymbol{g})}+3 \mathrm{H}_{2(\boldsymbol{g})} \longrightarrow 2 \mathrm{NH}_{3(\boldsymbol{g})}$
$\therefore \Delta n=2-4=-2$
$\therefore \Delta H=\Delta U+\Delta n R T=\Delta U-2 R T$