${C_{\left( {graphite} \right)}} + {O_{2\left( g \right)}} \to C{O_{2\left( g \right)}}\,;\Delta H = - 393.5\,kJ$
${H_{2\left( g \right)}} + 1/2{O_{2\left( g \right)}} \to {H_2}{O_{\left( l \right)}}\,;\,\Delta H = - 286.2\,kJ$
${C_2}{H_{4\left( g \right)}} + 3{O_{2\left( g \right)}} \to 2C{O_{2\left( g \right)}} + 2{H_2}{O_{\left( l \right)}}\,;\,\Delta H = - 1410.8\,kJ$
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.)
$C$ $($હીરા$)$ $ + {O_2}(g) \to C{O_2}(g);\,\Delta H = - 393.5$
જો ગ્રેફાઇટથી હીરો બને તો ઉપરના આંકડા પરથી $\Delta H$.......$kJ$