Liquid butane (C4H10) and liquid propane (C3H8) are often stored in cylinders, to be used as fuels. The normal boiling point of butane is -0.5 °C and its ΔHvap is 23.1 kJ/mol. The corresponding values for propane are -42.1 °C and 15.4 kJ/mol, respectively.
How much energy is required to vaporize 165 g of butane at its boiling point? The heat of vaporization for butane is 23.1 kJ/mol.
Express your answer to three significant figures and include the appropriate units.