Viscosities, Apparent Molar Volumes, Expansivities and Isentropic Compressibilities of some Fatty Acids and their Triglycerides in Benzene at (20, 30, 40 and 60) °C

Viscosities, apparent molal volumes, compressibilities and expansivities of lauric, palmitic and stearic acids and their triglycerides, trilaurin, tripalmitin and tristearin, were determined in benzene at 20, 30, 40 and 60 °C. Accurate density and sound velocity measurements carried out simultaneously with a high-precision vibrating-tube densimeter and sound velocity measuring device were utilized in deriving volume, compressibility and expansivity data. Viscosities were measured with Ostwald type viscometers. Infinite dilution values of the apparent molal volumes and compressibilities were obtained by an extrapolation procedure. Apparent molal expansivities at infinite dilution were obtained from the temperature dependence of the apparent molar volume at infinite dilution. The properties at infinite dilution were evaluated in terms of solute-solvent interactions. Volumetric results in benzene were compared with the corresponding data estimated from group contributions in aqueous solutions using the additivity rule.