\(\Delta S = R\,\ln \,\frac{{{P_1}}}{{{P_2}}} = 8.314\,ln\,2\)
\( = 8.314 \times 0.693 = 5.76\,J{K^{ - 1}}\,mo{l^{ - 1}}\)
$CaO_{(s)}\,\, + \,\,{H_2}O_{(l)}\,\, \to \,\,Ca{(OH)_2}_{(s)}\,;\,\,\,........(i)$ $\,\Delta {H_{1.8\,^oC}} = \,\, - \,\,15.26\,\,K\,cal$
$H_2O_{(l)}\,$ $ \to $ ${H_{2{(g)}}}$ $+$ $\frac{1}{2}O_{2(g)}$ $\,\Delta {H_{1.8\,^oC}} = \,\, - \,\,68.37\,\,K\,cal$
$Ca_{(s)} + \frac{1}{2}O_{2(g)} = CaO_{(s)}$ $\,\Delta {H_{1.8\,^oC}} = \,\, \,\,-151.80\,\,K\,cal$
આપેલ :$\Delta_{ dis } H _{ Cl _{2(g)}}^{\circ}=240\,kJ\,mol ^{-1}$.
$\Delta_{ eg } H _{ Cl _{(g)}}^{\circ}=-350\,kJ\,mol ^{-1}$,
$\Delta_{ hyd } H _{ Cl i _{( j )}^{\circ}}^{\circ}=-380\,kJ\,mol ^{-1}$
$Mg^{2+}(aq) = -456.0; OH-(aq) = -1 57.3; Mg(OH)_2 (s) = -833.9$
$ C(s)\,\, + \,\,{O_2}(g)\,\, \to \,\,C{O_2}\,(g)$ $\Delta H = \,\, - \,94\,\,kcal$
${H_2}\,(g)\,\, + \,\,\frac{1}{2}\,{O_2}\,(g)\,\, \to \,\,{H_2}O\,(g),$ $\Delta H\,\, = \,\, - \,68\,\,kcal$
${C_2}{H_5}OH\,(\ell )\,\, + \,\,3{O_2}\,(g)\,\, \to \,\,2C{O_2}\,(g)\,\, + \,\,3{H_2}O\,(\ell ),$$\Delta H\,\, = \,\,\, - \,327\,\,kcal$