$\therefore \,\,\Delta G\,\, = \,\,\Delta H - T\Delta S\,\,\,\,\,\therefore \,\,\,0\,\, = \,\,\Delta H\, - \,T\Delta S\,\,\,\,\therefore \,\,\Delta H\,\, = \,\,T\Delta S$
$\therefore \,\,\,\,T\,\, = \,\,\frac{{\Delta H}}{{\Delta S}}\,\, = \,\,\frac{{30 \times {{10}^3}}}{{105}}\,\, = \,\,285.7\,K$
$CaO_{(s)}\,\, + \,\,{H_2}O_{(l)}\,\, \to \,\,Ca{(OH)_2}_{(s)}\,;\,\,\,........(i)$ $\,\Delta {H_{1.8\,^oC}} = \,\, - \,\,15.26\,\,K\,cal$
$H_2O_{(l)}\,$ $ \to $ ${H_{2{(g)}}}$ $+$ $\frac{1}{2}O_{2(g)}$ $\,\Delta {H_{1.8\,^oC}} = \,\, - \,\,68.37\,\,K\,cal$
$Ca_{(s)} + \frac{1}{2}O_{2(g)} = CaO_{(s)}$ $\,\Delta {H_{1.8\,^oC}} = \,\, \,\,-151.80\,\,K\,cal$
તો $2ZnS + 3O_2$ $\rightarrow$ $2ZnO + 2SO_3$ પ્રક્રિયા માટે $\Delta\, G^o$ નું મૂલ્ય .......$J$