Thermodynamic properties of (a propyl ester plus an n-alkane). XII. Excessmolar enthalpies and excess molar volumes for {xCH(3)(CH2)(u-1)COO(CH2)(2)CH3+(1-x)CH3(CH2)(2v+1)CH3} with u = (1 to 3), and v = (1 to 7)

Excess molar enthalpies H-m(E) and excess molar volumes V-m(E) were determi ned at the temperature 298.15 K for 21 binary mixtures of three propyl este rs (ethanoate, propanoate, and butanoate) and seven odd n-alkanes (pentane to heptadecane). All the mixtures exhibited endothermic enthalpies which de creased quasi-exponentially with the ester chain length in the same proport ion as their dipole effects. The variations of the excess molar volumes for these mixtures followed a similar decreasing trend, with contractions obse rved in the systems consisting of high molar mass esters and lowest n-alkan es. These effects have been interpreted on the basis of molecular interacti ons. The UNIFAC, DISQUAC, and Nitta-Chao models were used to estimate the t hermodynamic properties considered, and yielded acceptable results. (C) 199 9 Academic Press.