Abstract: The apparent and partial molar volumes have been determined dilatometrically for he-xane in ethanol and five ethanol-water mixtures at 303.15K.The results showed that theapparent and partial molar volumes of hexane in ethanol or aqueous solution of ethanol arelarger than the molar volume of pure hexane and very sensitive to the presence of water inethanol in the hydrocarbon-dilution region.A linear relationship was observed between thelimiting apparent molar volume of hexane and molar fraction of water in ethanol-water mix-tures.

Key words: apparent molar volume, partial molar volume, alkane-alcohol-water mixture