\(\Delta S\, = \,\,\frac{{\Delta {H_{Vap}}}}{{{T_{Vap}}}}\)
\(\Delta \,\,{H_{vap}}\, = \,\,{\text{40}}{\text{.8}}\,\,{\text{KJ}}\,\,{\text{mo}}{{\text{l}}^{ - 1}}{\text{ }}\, = \,\,{\text{40}}{\text{.8}}\,\, \times \,\,{\text{1000}}\,\,{\text{J}}\,\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\) અને \(T\,\, = \,\,373\,\,K\)
\(\therefore \,\,\Delta S\,\, = \,\,\frac{{40.8\,\, \times \,\,1000\,\,J\,mo{l^{ - 1}}}}{{373\,K}}\)
\( \Rightarrow \,\,\Delta S\,\, = \,\,109.38\,\,J{K^{ - 1}}\,mo{l^{ - 1}}\)
$(i)$ $N_2H_4$$_{(l)}$ $+$ $2H_2O_2$$_{(l)}$ $\rightarrow$ $N_2$$_{(g)}$ $+$ $4H_2O$$_{(l)}$; $\Delta r{H_1}^ \circ = - 818 \,kJ/mol$
$(ii)$ $N_2H_4$$_{(l)}$ $+$ $O_2$$_{(g)}$ $\rightarrow$ $N_2$$_{(g)}$ $+$ $2H_2O$$_{(l)}$; $\Delta r{H_2}^ \circ = - 622 \,kJ/mol$
$(iii)$ ${H_2}_{(g)}\,\, $+$ \,\,\frac{1}{2}\,{O_2}_{(g)}\,\, \to \,\,{H_2}O_{(l)}\,\,\,;\,\,{\Delta }r{H_3}^ \circ \, = \,\, - 285\,\,kJ/mol$
$(I)$ ધનનુ ગલન $(II)$ વાયુઓને મિશ્ર ક્રરવા
$(III)$ વાયુનુ સંકોચન $(IV)$ વાયુનુ વિસ્તરણ