Partial molar volume of n-alcohols at infinite dilution in water calculated by means of scaled particle theory.
The partial molar volume of n-alcohols at infinite dilution in water is smaller than the molar volume in the neat liquid phase. It is shown that the formula for the partial molar volume at infinite dilution obtained from the scaled particle theory equation of state for binary hard sphere mixtures is able to reproduce in a satisfactory manner the experimental data over a large temperature range. This finding implies that the packing effects play the fundamental role in determining the partial molar volume at infinite dilution in water also for solutes, such as n-alcohols, forming H bonds with water molecules. Since the packing effects in water are largely related to the small size of its molecules, the latter feature is the ultimate cause of the decrease in partial molar volume associated with the hydrophobic effect.
Graziano
Giuseppe
G
Dipartimento di Scienze Biologiche ed Ambientali, Università del Sannio, Via Port' Arsa, 11-82100 Benevento, Italy. graziano@unisannio.it