$A.$ $I _2( g ) \rightarrow 2 I ( g )$
$B.$ $HCl ( g ) \rightarrow H ( g )+ Cl ( g )$
$C.$ $H _2 O ( l ) \rightarrow H _2 O ( g )$
$D.$ $C ( s )+ O _2( g ) \rightarrow CO _2( g )$
$E.$ પાણીમાં એમોનિયમ કલોરાઈડનું વિલયન (ઓગળવું)
$B \rightarrow$ Endothermic (Atomisation)
$C \rightarrow$ Endothermic (Vapourisation)
$D \rightarrow$ Exothermic (Combustion)
$E \rightarrow$ Endothermic (Dissolution)
આપેલ : $\Delta H ^{\circ}=-54.07\,kJ\,mol ^{-1}$
$\Delta S ^{\circ}=10\,J\,K ^{-1}\,mol ^{-1}$
$(2.303 \times 8.314 \times 298=5705$ લો.)
$(i)$ $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$
${N_2} + 3{H_2}$ $\rightleftharpoons$ $2N{H_3}$