The first step in the preparation of lead from its ore (galena, PbS) consists of roasting the ore.
2PbS(s) + 3O2(g) ? 2SO2(g) + 2PbO(s)
Calculate the standard enthalpy change for this reaction using enthalpies of formation.
?H°f (PbS(s)) = -98.32 kJ
?H°f (SO2(g)) = -296.8 kJ
?H°f (PbO(s)) = -219.4 kJ