Thermodynamics of dissolving gaseous argon in different solvents

The solvation of argon in 10 different solvents at room temperature is analysed in terms of the theoretical framework developed by Lee. In order to perform calculations, we used the approach devised by Pierotti and firmly validated by Lee's theory. The fair agreement between the experimental and the calculated values of Δ G. Δ H. , and Δ S. is carefully analysed. It proves that the excluded volume effect, due to cavity creation in the solvent, opposes the solubility process. This effect in water is exaggerated by the small size of the water molecules and is the cause of hydrophobicity. The qualitative difference between water and hydrazine with regard to the solvation enthalpy and entropy changes is rationalized on the basis of the contributions arising from the structural reorganization in the two solvents on solute insertion.Key words: hydrophobic hydration, cavity creation, structural solvent reorganization.