$2C_8H_{18}$ $_{(g)}$ + $25O_2$ $_{(g)}$ $\rightarrow$ $16CO_2$$_{(g)}$ + $18H_2O$ $_{(g)}$
$N \equiv N\,\left( {946\,kJ\,mo{l^{ - 1}}} \right)\,;\,N = N\,\left( {418\,kJ\,mo{l^{ - 1}}} \right)$
$O = O\,\left( {498\,kJ\,mo{l^{ - 1}}} \right)\,;\,N = O\,\left( {607\,kJ\,mo{l^{ - 1}}} \right)$;
${H_2}C = C{H_2}(g) + {H_2}(g) \to {H_3}C - C{H_3}(g)$