Final answer:
Ethanol (C₂H₅OH) would have the highest boiling point among the given compounds due to its ability to form hydrogen bonds, which are much stronger than the London dispersion forces present in the other molecules.
Step-by-step explanation:
The boiling point of a substance is influenced by the type and strength of intermolecular forces (IMFs) present in the substance. There are three primary types of IMFs: London dispersion forces, dipole-dipole interactions, and hydrogen bonding.
Methane (CH₄) and other alkanes are nonpolar molecules, so they exhibit only London dispersion forces, which are relatively weak. As molecular mass increases, these London dispersion forces become stronger due to a larger electron cloud that can be more easily polarized. Hence, larger alkanes have higher boiling points.
Ethanol (C₂H₅OH), on the other hand, can participate in hydrogen bonding due to its -OH group, in addition to dipole-dipole interactions and London dispersion forces. Hydrogen bonds are much stronger than the other types of IMFs, so ethanol has a significantly higher boiling point.
Therefore, among the given options, Ethanol would have the highest boiling point because it is capable of strong hydrogen bonding, which greatly increases the amount of energy required to change its state from liquid to gas.