The combustion of ethene, C2H4 , occurs via the reaction C2H4 (g) + 3O2(g) ===> 2CO2(g) + 2H2O(g) with heat of formation values given by the following table: Substance Delta H f (kJ/mol) (\rm kJ/mol) C2H4 (g) 52.47 CO2(g) -393.5 H2O(g) -241.8 Calculate the enthalpy for the combustion of ethene.