Final answer:
The boiling point of ethanol is higher than that of ethers and alkanes of similar molar mass due to the ability of ethanol's OH group to engage in hydrogen bonding. This also explains why alcohols are more soluble in water compared to alkanes.
Step-by-step explanation:
The boiling point of a substance is influenced by the strength of the intermolecular forces (IMFs) present in the substance. In this case, we are comparing the boiling points of ethanol with other compounds such as ethers and alkanes.
First, let's consider ethanol, which has an OH group. This group is capable of forming hydrogen bonds, which are particularly strong dipole-dipole interactions that occur between a hydrogen atom attached to a highly electronegative atom (like oxygen) and another electronegative atom with a lone pair of electrons.
In comparison, ethers, which have an oxygen atom, can form dipole-dipole interactions but cannot engage in hydrogen bonding because they lack a hydrogen atom directly bonded to the electronegative oxygen. Alkanes are mostly nonpolar, and so they can only exhibit London dispersion forces, which are the weakest form of IMFs.
Given that hydrogen bonding is much stronger than dipole-dipole and dispersion forces, ethanol will have a higher boiling point than ethers and alkanes of a similar molar mass. Furthermore, the solubility of alcohols like ethanol in water is also high due to their ability to engage in hydrogen bonding with water molecules. In contrast, alkanes cannot form these strong interactions and are not soluble in water.