London Dispersion Forces

London Dispersion Forces Definition:

The London dispersion forces are attractive forces between that exist between non-polar molecules.

London Dispersion Forces Explained:

The London dispersion force occurs because of the formation of instantaneous dipoles in non-polar molecules. This happens because of fo the shifting electron clouds in the molecule. In most cases, the net dipole on a non-polar molecule is zero, however, under certain instances, the net dipole moment is not zero. This occurrence of an instantaneous dipole is the cause of attractive forces called London dispersion forces. The effect of this force is stronger in molecules of higher molecular weight which also explains their higher boiling points.

Points to note –

  • The boiling point of hydrocarbons increases with molecular weight
  • The boiling point of hydrocarbons decreases with branching.