$(i)$ $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$
$\left[\right.$ ઉપયોગ $: {H}^{+}({aq})+{OH}^{-}({aq}) \rightarrow {H}_{2} {O}: \Delta_{{\gamma}} {H}=-57.1\, {k} {J} \,{mol}^{-1},$
વિશિષ્ટ ઊર્જા ${H}_{2} {O}=4.18 {Jk}^{-} {g}^{-},$
ઘનતા ${H}_{2} {O}=1.0\, {~g} {~cm}^{-3},$
મિશ્રણ પર દ્રાવણના કદમાં કોઈ ફેરફાર થતો નથી એમ ધારો.]