Boiling point is a measure of the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid is affected by several factors, including intermolecular forces. Intermolecular forces are the forces that act between molecules. There are three main types of intermolecular forces: hydrogen bonding, dipole-dipole forces, and London dispersion forces.

Hydrogen bonding is the strongest of the three intermolecular forces. It occurs when a hydrogen atom is bonded to a highly electronegative atom, such as nitrogen, oxygen, or fluorine. Dipole-dipole forces occur when two molecules have permanent dipoles. London dispersion forces are the weakest of the three intermolecular forces. They occur when electrons move around the nucleus of an atom, creating a temporary dipole.

The boiling point of a liquid is directly proportional to the strength of the intermolecular forces between the molecules. The stronger the intermolecular forces, the higher the boiling point. Therefore, hydrogen bonding would affect the boiling point the most, followed by dipole-dipole forces, and then London dispersion forces.