સમીકરણ $(1)$ : $2C\,\, + \,\,2{O_2}\, \to \,\,2C{O_2}\,:\,\,\Delta \,H\,\, = \,\, - 787$ કિલોજૂલ
સમીકરણ $(2)$ : $\,{H_2} + \frac{1}{2}{O_2} \to {H_2}O\,\,:\,\,\Delta H\,\, = \,\, - 286$ કિલોજૂલ
સરવાળો કરતાં : $2C\,\, + \,\,{H_2}\, \to \,\,{C_2}{H_2}\,\,\,\,\therefore \,\,\Delta H\,\, = \,\,237$ કિલોજૂલ
$\Delta {H_{{C_2}{H_2}}}\,\, = \,\,237$