Why do compounds with strong intermolecular attractive forces have higher boiling points than compounds with weak intermolecular attractive forces?

Answer 1

Heat is simply an expression of how fast molecules are vibrating and moving about, for the purposes of state of matter. Intermolecular bonds are what stop this motion from happening, so the stronger this bond, the higher the temperature needs to be for the compound to melt or boil.

Answer 2

The strong intermolecular forces reduced the tendency of evaporation of a liquid therefore high amount of heat is required to equalise the vapour pressure to atmospheric pressure, which is requirement for boiling so such liquids have high boiling points.

Answer 3

The stronger the intermolecular forces, the higher the boiling point. This occurs because energy must first go into breaking the intermolecular bonds. Once these bonds are broken, the molecules can then gain enough energy to break free of the liquid phase.