Group Additivity Analysis of the Heat Capacity Changes Associated with the Dissolution into Water of Different Organic Compounds

A group additivity approach is applied to the large positive heat capacity changes associated with the dissolution process into water of different classes of organic molecules. The results show that the contribution of nonpolar CH groups is approximately constant for all the organic molecules studied, regardless of their chemical nature and originating phase. Further analysis leads to the conclusion that the unique properties of water are the main physical cause of these results.