# Validity of Trouton's Rule

I would like to know under what circumstances is Trouton's rule obeyed by liquids and why certain systems i.e. substances may deviate from Trouton's rule.

By the way I know what Trouton's rule is and I have a vague idea that sometimes Trouton's rule is not obeyed due to the presence of hydrogen bonding in liquids such as water but I would like to know more about other reasons why certain situations the rule is invalid.

The rule says that for many liquids the entropy of vaporization is almost the same, around ${\rm 85\,J K^{-1}}$.
It's true that the rule states that entropy of vapourization is $85 – 88~\mathrm{J/K}$.However, the rule hardly works for high ordered substances exhibiting hydrogen bonding.