Excess properties of liquid mixtures from perturbation theory: results for model systems and predictions for real systems
1985; Elsevier BV; Volume: 23; Issue: 2-3 Linguagem: Inglês
10.1016/0378-3812(85)90002-0
ISSN1879-0224
AutoresMichael Bohn, Santiago Lago, Johann Fischer, Frank Köhler,
Tópico(s)Chemical Thermodynamics and Molecular Structure
ResumoMixtures consisting of spherical and linear molecules are treated with a Weeks-Chandler-Andersen type perturbation theory. For model mixtures of spherical molecules the excess properties obtained from perturbation theory are in excellent agreement with the simulation results of Singer for all energy and size ratios. The concentration dependence of the excess properties is investigated and shown to become asymmetric for gE only as a consequence of different molecular sizes. For mixtures of spherical with linear molecules the effect of the molecular shape on the excess quantities is demonstrated. As to the properties of real mixtures, for spherical or nearly spherical molecules they can be predicted with fair accuracy using merely pure component properties by applying a previously suggested combinating rule or its improvement. Finally, an extension of the combining rule to nonspherical molecules is attempted and yields good predictions for the mixtures Ar/C2H6, CH4/C2H6, Kr/C2H6 and Xe/C2H6.
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