\( \Delta \mathrm{U}=\mathrm{Q}+\mathrm{W}, \)
\( \Delta \mathrm{U}=0: \text { Process is isothermal } \)
\( \mathrm{Q}=-\mathrm{W} \)
\( \mathrm{W}=-\mathrm{P}_{\text {ext }} \Delta \mathrm{V}: \text { Irreversible } \)
\( =-80 \times 10^3(45-30) \times 10^{-3} \)
\( =-1200 \mathrm{~J}\)
આપેલ :$\Delta_{ dis } H _{ Cl _{2(g)}}^{\circ}=240\,kJ\,mol ^{-1}$.
$\Delta_{ eg } H _{ Cl _{(g)}}^{\circ}=-350\,kJ\,mol ^{-1}$,
$\Delta_{ hyd } H _{ Cl i _{( j )}^{\circ}}^{\circ}=-380\,kJ\,mol ^{-1}$