H-bonding is the strongest of the
Intermolecular Forces (IMF's). This occurs when a hydrogen
atom is bonded directly to and atom of fluorine, oxygen or nitrogen.
The "FON" sisters. This hydrogen being so small and F,O or N also
being really small and very electronegative will create a very
strong attractive force between the hydrogen of one molecule and the
F,O or N in another molecule.
This
force is so strong that it cause an abnormally high boiling point
then expected for a molecule of similar size and polarity.
Notice the trend for a molecules with
hydrogen bonded to a group 14 element. The less massive molecules
have a low boiling point. This trend does not work for HF, H2O
and NH3 due to the presence of H-bonding.
