What is the enthalpy change for the following reaction: C3H8(g) + 5O2 (g) --> 3CO2 (g) + 4H2O (l)ΔHof C3H8 (g) = -103.8 kJΔHof CO2 (g) = -393.5 kJΔHof H20 (l) = -285.8 kJ