Hydrazine, N2H4 , has been used as a rocket fuel because its reaction with oxygen is extremely exothermic:

N2H4(l) + O2(g) -> N2(g) + 2H2O(g) H=-534.0kJ

The enthalpy change for the vaporization of water is given by:

H2O(l) -> H2O(g) H= 40.7kJ

Calculate the enthalpy change that would result if the water were produced in liquid rather than the gaseous form.
N2H4(l) + O2(g) -> N2(g) + 2H2O(l) H=?