Calculate the change in enthalpy for the reaction of one mole of PbO2 from lead and oxygen at 550C. Given: Pb + 1/2 O2 = PbO, H298 = 219242 J. mol1 Pb 3PbO + 1/2 O2 = Pb3O4, H298 = 76986 J.mol1 PbO Pb3O4 + O2 = 3PbO2, H298 = 94977 J. mol1 O2 Cp(Pb) = 38.4 + 1.9 10^-3T Cp(O2 ) = 28.6 + 1.4 10^-3T 8.4 105T 2 Cp(Pb) = 76.2 4.6 x 10^-3T