PREDICTION OF SPEEDS OF SOUND AND ULTRASONIC STUDIES OF HYDROXYETHER + ORGANIC SOLVENT MIXTURES
Advancing the chemical engineering fundamentals
Thermodynamics (T2-1P)
Keywords: hydroxyethers; solvents; predictions; ultrasonic; Rao's constant
As a part of a systematic study of mixtures containing hydroxyethers [1,2], we present a comparison between predictions on speeds of sound from different models for this type of systems. Particularly, the hydroxyethers considered are: 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 2-isopropoxyethanol, 2-isobutoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, 2-(2-butoxyethoxy)ethanol, 2-{2-(2-methoxyethoxyethoxy)}ethanol, 2-{2-(2-ethoxyethoxyethoxy)}ethanol and 2-{2-(2-butoxyethoxyethoxy)}ethanol. The organic solvents are: octane, dibutylether, polyethers, acetals, and propylamine. There is a number of theories, based in the intermolecular free length concept, which provide speeds of sound values on the basis of different expressions of the available volume. Here, we have considered the free length theory (FLT) and the collision factor theory (CFT). In addition, we have also used empirical equations such as Nomoto’s equation, Junjie’s equation and the Van Dael’s equation, the two latter based on the ideal solution concept for the isoentropic compressibility. The mean standard relative deviations, for the 30 systems considered are: 0.030 (LFT); 0.013 (CFT); 0.010 (Nomoto); 0.010 (Junjie) and 0.033 (Van Dael). The poorer results are obtained from the Van Dael’s equation for the systems with propylamine, which can be ascribed to the strong interactions between unlike molecules present in such solutions. On the other hand, the Rao’s constant varies linearly on the concentration. This indicates that there is no association between unlike molecules [3] in the studied mixtures and that the interactions are of dipolar type [2].
[1] J.A. González, J.C. Cobos, F.J. Carmona, I. García de la Fuente, V.R. Bhethanabotla, S.W. Campbell, Phys. Chem. Chem. Phys., 3 (2001) 2856-2865.
[2] I. Mozo, I. García de la Fuente, J.A. González, J.C. Cobos, J. Mol. Liq., 129 (2006) 155-163.
[3] P.S. Ramesh, D. Geetha, C. Rakkappan, J. Mol. Liq., 126 (2006) 69-71
ACKNOWLEDGEMENTS
The authors gratefully acknowledge the financial support received from the Consejería de Educación y Cultura of Junta de Castilla y León, under Project VA080A06.
Presented Monday 17, 13:30 to 15:00, in session Thermodynamics (T2-1P).
