1. The combustion of H2S in oxygen is as follows: 2H2S(g)+3O2(g)2H2O(g)+2SO2(g) Given the following data, what is the heat of combustion of H2S ? (1) H2(g)+S(s)H2S(g) H=40.2kJ/mol (2) H2(g)+1/2O2(g)H2O(g) H=242kJ/mol (3) S(s)+O2(g)SO2(g) H=297kJ/mol