If $\Delta \mathrm{G}$ and $\Delta \mathrm{S}$ for the reaction $\mathrm{A}(\mathrm{g}) \rightarrow…
If $\Delta \mathrm{G}$ and $\Delta \mathrm{S}$ for the reaction $\mathrm{A}(\mathrm{g}) \rightarrow \mathrm{B}(\mathrm{g})+2 \mathrm{C}(\mathrm{g})$ at $2000 \mathrm{~K}$ are $-40 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $0.22 \mathrm{~kJ} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ respectively, the change in internal energy for the same reaction approximately (in $\mathrm{kJ} \mathrm{mol}^{-1}$ ) is
$366.7$
$-366.7$
$400$
$-400$
Solution
$\begin{aligned}
& \Delta u=\Delta U-T \Delta S \\
& \Delta U=\Delta G+T \Delta S \\
& \Delta U=-40+(2000 \cdot(0.22)) \\
& \Delta u=-40+440 \mathrm{~kJ} \mathrm{mal}^{-1} \\
& \Delta U=400 \mathrm{~kJ} \mathrm{~mol}-1
\end{aligned}$
$\therefore$ Ans is option c) 400