A comparative study of thermodynamic properties of binary mixtures containing dimethylsulfoxide

Abstract

A flow microcalorimeter has been used to determine excess enthanlpies (H E) at 298.15 K for binary mixtures of dimethylsulfoxide (1)+alkylbenzenes (benzene, methylbenzene, ethylbenzene, n-propylbenzene and sec-propylbenzene, n-butylbenzene, sec-butylbenzene and tert-butylbenzene) or tetrachloromethane, trichloromethane, tetrachloroethane, dichloromethane and monochloroalkanes (1-chloropropane, 1-chlorobutane, 1-chloropentane, 1-chlorohexane) (2). These data with the data available in the literature on the molar excess enthalpies (H E), molar excess Gibbs energies (G E), activity coefficients at infinite dilution, γ i ∞ , liquid-vapour equilibria (LVE) and liquid-liquid equilibria (LLE) for dimethylsulfoxide (DMSO)+n-alkanes, cyclohexane, benzene or alkylbenzenes (mono-, dialkyl-and trialkyl-) or tetrachloromethane, trichloromethane, dichloromethane and monochloroalkanes are treated in the framework of DISQUAC, an extended quasi-chemical group contribution theory. The systems are characterized by three types of contact surfaces: sulfoxide (S=O group), aliphatic (CH3, CH2, CH groups), cycloaliphatic (c-CH2 group), aromatic (C6H6, C6H5 groups) and chlorine (C1 group). Using a set of adjusted contact interchange energies parameters, structure dependent, the model provides a fairly consistent description of the thermodynamic properties as a function of concentration. The model may serve to predict missing data.