(I) $C_{(graphite)}+O_2 (g) \longrightarrow CO_2(g); \Delta H=393.5\;kJ$
(II) $H_2(g)+\large\frac{1}{2}$$O_2 (g) \longrightarrow H_2O(l); \Delta H=-286.2\;kJ$
(III) $C_2H_4(g)+3O_2 (g) \longrightarrow 2CO_2(g)+2H_2O(l) \; \Delta H=-1410.8\;kJ$
\[\begin {array} {1 1} (a)\;54.1\;kJ & \quad (b)\;44.8\;kJ \\ (c)\;51.4\;kJ & \quad (d)\;48.4\;kJ \end {array}\]