The enthalpy of vaporization of substance e is smaller than that of substance f. Which has the higher boiling point?
The enthalpy of vaporization is the amount of energy required to convert a substance from a liquid to a gas phase at its boiling point. A smaller enthalpy of vaporization indicates that less energy is needed to convert the substance into a gas, which in turn suggests that the substance has a higher propensity to vaporize and a lower boiling point.
Therefore, substance e, with a smaller enthalpy of vaporization, will have a higher boiling point compared to substance f, which has a larger enthalpy of vaporization.