Solvation of a water molecule in cyclohexane and water

Reliable values for the thermodynamic functions associated with the solvation of a water molecule in its own liquid phase and in cyclohexane, at 25 degreesC, are obtained using experimental data from different investigations. They are successfully rationalized by means of a general theory of solvation. The standard Gibbs energy change is given by the balance of two contrasting terms: the work to create a cavity in the solvent suitable to host the water molecule; and the work to turn on the water-solvent interactions. It proves that the work of cavity creation is largely overwhelmed by the formation of two H-bonds in liquid water, whereas it is almost exactly counterbalanced by the establishment of van der Waals interactions in liquid cyclohexane.