An 18.0 g sample of water at 100 °C and an 18.0 g sample of ethanol at its boiling point are each completely vaporized. The molar enthalpy of vaporization of water is 40.7 kJ mol⁻¹, and that of ethanol is 38.6 kJ mol⁻¹. Calculate the heat required for each sample and indicate which sample requires more energy.