Question

Ethanol has a higher boiling point than diethyl ether or ethylamine. Why ?

Answer 1

Intermolecular forces are the forces that exist between molecules. The greater the boiling point, the stronger the intermolecular force between the molecules. H-bonding exists in ethanol, but not in diethyl ether (because the O-atom is connected to the C-atom), and the H-bonds created by the n-atom in ethyl amine are weaker than those formed by the O-atom.

Complete answer:
The hydroxyl group is a highly polar functional group found in alcohols. As a result, the $OH$ group's oxygen draws the $OH$ bond's shared electron pair towards itself.
As a result, the $OH$ group's oxygen has a partial negative charge, while hydrogen has a partial positive charge.
One molecule's negative oxygen interacts with another's positive hydrogen. Hydrogen bonding is the name for this type of interaction. As a result, a high number of alcohol molecules are firmly linked.
As a result, a significant amount of energy must be supplied to dissolve this connection. As a result, the boiling points of alcohol are greater.
This form of hydrogen bonding does not exist in ethers. As a result of the decreased intermolecular interaction, ethers boil at lower temperatures.
Because of this, ethanol has a higher boiling point than diethyl ether.

Note:
To answer these questions, you'll need to understand intermolecular forces of attraction like hydrogen bonding, Vander wall forces, and others. Ionic bonds $>$ Hydrogen bonds $>$ Van der Waals dipole-dipole interactions $>$ Van Der Waals dispersion forces are the relative strengths of the bonding forces.