Thermodynamics of mixtures with strongly negative deviations from Raoult’s law. Part 8. Excess molar volumes at 298.15 K for 1-alkanol + isomeric amine (C 6H 15N) systems : Characterization in terms of the ERAS model

• Published in: Fluid phase equilibria Vol. 216; no. 1; pp. 123 - 133
• Main Authors: Villa, S, Riesco, N, Garcı́a de la Fuente, I, González, J.A, Cobos, J.C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.02.2004; Elsevier Science
• Subjects: 1-Alkanol; Chemistry; ERAS model; Exact sciences and technology; Experimental; General and physical chemistry; Interactions; Isomeric amine; Packing effects; Phase equilibria; Experimental; V E; Interactions; Packing effects; 1-Alkanol; Isomeric amine; ERAS model; Molar volume; Interaction; Excess parameter; Mixture; VE; Thermodynamics; Amine; Packing; Alkanol; Models; Thermodynamic properties; Phase equilibrium
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/j.fluid.2003.10.008

Excess molar volumes, V E, at 298.15 K and atmospheric pressure, over the entire composition range for binary mixtures of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol with hexylamine (HxA) and of 1-propanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol with triethylamine (TEA) are reported. They are calculated from densities measured with a vibrating-tube densimeter. All the excess volumes are large and negative over the whole mole fraction range, indicating strong interactions between unlike molecules. These interactions are stronger for the solutions with methanol or ethanol. The corresponding values of the molar excess enthalpies, H E, and of the molar excess internal energies confirm this point. At equimolar composition, V E values for the 1-alkanol + HxA systems behave similarly to those of other systems previously investigated such as 1-alkanol + dipropylamine (DPA), + dibutylamine, or + methyl butylamine. For these mixtures, the main contribution to the V E seems to be due to the interactional term. In contrast, packing effects are much more important in 1-alkanol + TEA mixtures. V E and H E of the studied solutions are consistently described by the ERAS model. The ERAS parameters point out that the strongest interactions between unlike molecules are encountered in the solutions including methanol.