Excess molar volumes and excess molar enthalpies of binary and ternary mixtures of (ethanol or 1-butanol), triethylamine and n-hexane

Experimental data at 298.15 K and ambient pressure of excess molar volumes V-m(E) and excess molar enthalpies H-m(E) are reported for two ternary and corresponding binary mixtures of an alkanol (ethanol or 1-butanol), triethylamine (TEA) and n-hexane. A vibrating-tube densitometer was used to determine V-m(E). H-m(E) was measured using a quasi-isothermal flow calorimeter. The experimental results are used to test the applicability of the ERAS model for describing both thermodynamic excess properties of ternary mixtures containing an alkanol, a tertiary amine and a n-alkane. Qualitative agreement of calculated values with experimental results was achieved using only system-specific parameters determined from binary mixtures. The results are explained in terms of the self-association between alkanol molecules and cross-association between the alkanol and the tertiary amine. (c) 2005 Elsevier B.V. All rights reserved.