Question

How can I identify intermolecular forces?

Answer 1

Usually the boiling point is the best indicator of the extent of intermolecular forces.

Explanation:

Low boiling points are associated with negligible intermolecular force. High boiling points indicate substantial intermolecular force. In order of magnitude, intermolecular forces include (i) hydrogen bonding, where hydrogen is bound to a strongly electronegative element; (ii) dipole-dipole, where the molecular dipoles align; and (iii) induced dipole and dispersion forces.

The elevated boiling points of `OH_2`, `NH_3`, and `HF` are the best indicators of the strength of H-bonding. Note that I have confined this answer to the forces between molecules, which presupposes molecular materials.