Ethyne (C2 H2 (g), Hf = 226.77 kJ/mol) undergoes complete combustion in the presence of oxygen to produce carbon dioxide (CO2 (g), Hf = –393.5 kJ/mol ) and water (H2 O(g), Hf = –241.82 kJ/mol) according to the equation below.What is the enthalpy of combustion (per mole) of C2 H2 (g)? Use .