Given that $\mathrm{C}_{(\mathrm{g})}+4 \mathrm{H}_{(\mathrm{g})} \longrightarrow…
Given that
$\mathrm{C}_{(\mathrm{g})}+4 \mathrm{H}_{(\mathrm{g})} \longrightarrow \mathrm{CH}_{4(\mathrm{~g})} \Delta \mathrm{H}^{\circ}=-1665 \mathrm{~kJ}$
What is bond energy per mole of $\mathrm{C}-\mathrm{H}$ bond ?
$416 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$\quad-416 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$832.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$\quad-832.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$
Solution
In the given reaction, there are $4 \mathrm{C}-\mathrm{H}$ bonds formed per mole of $\mathrm{CH}_4$. Bond energy per mole of
$\begin{aligned}
\mathrm{fCH}_4 & =\frac{-(-1665 \mathrm{~kJ})}{4} \\
& =416.25 \mathrm{~kJ}
\end{aligned}$