Chapter 14, Problem 50E

Ammonia (NH₃) boils at -33 °C; at this temperature it has a density of 0.81 g/cm³. The enthalpy of formation of NH₃(g) is - 46.2 kJ/mol, and the enthalpy of vaporization of NH₃(l) is 23.2kJ/mol. Calculate the enthalpy change when 1 L of liquid NH₃ is burned in air to give N₂(g) and H₂0(g). How does this compare withΔHfor the complete combustion of 1 L of liquid methanol, CH₃OH(l)?
For CH₃0H(l), the density at 25 °C is 0.792 g/cm³, andΔH°_f = - 229kJ /mol.