Estimation of dispersion and hydrogen bonding energies in liquids

Abstract
It is proposed that the product of the molar volume and the internal pressure is a measure of the dispersion interaction energy in liquids regardless of the presence of other intermolecular forces. If this is true, then the energy of interaction due to hydrogen bonding may be estimated for hydrogen bonding liquids by the difference between the energy of vaporization and the product of the molar volume and the internal pressure. It is also shown that Small's group contribution technique provides a good estimate of internal pressure of hydrogen bonding liquids.