$\Delta \mathrm{U}=\mathrm{nC}_{\mathrm{V}}\left[\mathrm{T}_{2}-\mathrm{T}_{1}\right]$
$\Rightarrow \quad 5000=4 \times \mathrm{C}_{\mathrm{V}}[500-300]$
$\Rightarrow \quad \mathrm{C}_{\mathrm{v}}=\frac{5000}{800}=6.25 \mathrm{J}$ $mole$ $^{-1} \mathrm{K}^{-1}$
| $H - H$ બંધઊર્જા | $:\, 431.37 \,kJ\, mol^{-1}$ |
| $C= C$ બંધઊર્જા | $:\, 606.10\, kJ \,mol^{-1}$ |
| $C - C$ બંધઊર્જા | $:\, 336.49\, kJ\, mol^{-1}$ |
| $C - H$ બંધઊર્જા | $:\, 410.50\, kJ\, mol^{-1}$ |
પ્રક્રિયા : $\begin{array}{*{20}{c}}
{H\,\,\,\,H} \\
{|\,\,\,\,\,\,\,\,|} \\
{C = C} \\
{|\,\,\,\,\,\,\,\,\,|} \\
{H\,\,\,\,H}
\end{array}\, + \,H - H\, \to \,\begin{array}{*{20}{c}}
{H\,\,\,\,H} \\
{|\,\,\,\,\,\,\,\,|} \\
{H - C - C - H} \\
{|\,\,\,\,\,\,\,\,\,|} \\
{H\,\,\,\,H}
\end{array}\,$
