Solubility of gases in water: Correlation between solubility and the number of water molecules in the first solvation shell

Using a new version of program called GEPOL, a consistent set of values for areas of three different kinds of surfaces for 53 gaseous solutes was comp uted by Silla et al. These surface areas, together with the volumes of spac e enclosed by the surfaces, are reported in the present paper. The three su rfaces are the van der Waals Surface (WS), the Solvent Accessible Surface ( SAS) and the Solvent-Excluding Surface (SES). Values for the number of wate r molecules (N) in the first solvation shell are estimated by a simple surf ace area approach from the SAS data. Values of N, as well as literature dat a on solubilities of gases in water, are used to study various semi-empiric al correlations between thermodynamic changes on solution and the number of water molecules in the first solvation shell.