\(\therefore \,\,\,(i)\,\frac{1}{2}{{H}_{2(g)}}+\frac{1}{2}C{{l}_{2(g)}}\to HC{{l}_{(g)}};\,\,\Delta {{H}^{o }}=-22\,Kcal\)
\( \,\,\,2N{{a}_{(s)}}+2HC{{l}_{(g)}}\to 2NaC{{l}_{(s)}}+{{H}_{2(g)}};\,\,\Delta {{H}^{o }}=-152\,\,Kcal\)
\(\therefore \,\,\text{(ii) }\,\,\text{N}{{\text{a}}_{\text{(s)}}}+HC{{l}_{(g)}}\to \text{NaC}{{\text{l}}_{\text{(s)}}}+\frac{1}{2}{{H}_{2(g)}}\Delta {{H}^{o }}=-76\,Kcal\)
\((i)\) અને \((ii)\) ઉમેરતા
\(\text{N}{{\text{a}}_{\text{(s)}}}+0.5\,\,\,C{{l}_{2(g)}}\to NaC{{l}_{(s)}};\,\,\Delta {{H}^{o }}=-98\,\,Kcal\)
$CO_2(g) , CO(g)$ અને $H_2O(g)$ માટે $\Delta H^o_f$ના મૂલ્યો અનુક્રમે $-393.5, -110.5$ અને $-241.8\, kJ/mol$,
$CO_2(g) + H_2(g) \to CO(g) + H_2O(g)$ is :