Use heat of formation data to determine ?H for the combustion of hydrogen sulfide according to the following reaction: 2 H2S(g) + 3 O2(g) ? 2 SO2(g) + 2 H2O(?) ?H = ? ?Hfo for compounds: H2S(g) is -20.15 kJ/mol , SO2(g) is -296.4 kJ/mol , H2O(?) is -285.8 kJ/mol