$\therefore \,\,\,(i)\,\frac{1}{2}{{H}_{2(g)}}+\frac{1}{2}C{{l}_{2(g)}}\to HC{{l}_{(g)}};\,\,\Delta {{H}^{o }}=-22\,Kcal$
$ \,\,\,2N{{a}_{(s)}}+2HC{{l}_{(g)}}\to 2NaC{{l}_{(s)}}+{{H}_{2(g)}};\,\,\Delta {{H}^{o }}=-152\,\,Kcal$
$\therefore \,\,\text{(ii) }\,\,\text{N}{{\text{a}}_{\text{(s)}}}+HC{{l}_{(g)}}\to \text{NaC}{{\text{l}}_{\text{(s)}}}+\frac{1}{2}{{H}_{2(g)}}\Delta {{H}^{o }}=-76\,Kcal$
$(i)$ અને $(ii)$ ઉમેરતા
$\text{N}{{\text{a}}_{\text{(s)}}}+0.5\,\,\,C{{l}_{2(g)}}\to NaC{{l}_{(s)}};\,\,\Delta {{H}^{o }}=-98\,\,Kcal$