Thermodynamic properties of (a propyl ester + ann-alkane). XII. Excess molar enthalpies and excess molar volumes for {xCH3(CH2)u − 1COO(CH2)2CH3 + (1 − x)CH3(CH2)2v + 1CH3} withu = (1to 3), andv = (1to 7)

Abstract

Excess molar enthalpiesHmEand excess molar volumesVmEwere determined at the temperature 298.15 K for 21 binary mixtures of three propyl esters (ethanoate, propanoate, and butanoate) and seven oddn-alkanes (pentane to heptadecane). All the mixtures exhibited endothermic enthalpies which decreased quasi-exponentially with the ester chain length in the same proportion as their dipole effects. The variations of the excess molar volumes for these mixtures followed a similar decreasing trend, with contractions observed in the systems consisting of high molar mass esters and lowestn-alkanes. These effects have been interpreted on the basis of molecular interactions. The UNIFAC, DISQUAC, and Nitta–Chao models were used to estimate the thermodynamic properties considered, and yielded acceptable results.