Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The densities (?) and refractive indices (n) of binary mixtures of 1,4-dioxane with benzene, toluene, o-xylene, m-xylene, p-xylene, and mesitylene, including those of pure liquids, over the entire composition range expressed by mole fraction x1 of 1,4-dioxane were measured at temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K under atmospheric pressure. From the experimental data, the excess molar volumes (VmE), deviations in refractive indices (?n), partial molar volumes (Vm,1deg ? and Vm,2deg ?), and excess partial molar volumes (Vm,1deg E,? and Vm,2deg E,?) of the components at infinite dilution were calculated. The VmE values were negative for 1,4-dioxane + benzene, positive for 1,4-dioxane + o-xylene, + m-xylene, + p-xylene, and + mesitylene mixtures over the entire mole fraction range at all investigated temperatures, and exhibit a sigmoid trend for1,4-dioxane + toluene mixtures wherein VmE changes sign from positive to negative as the mole fraction of 1,4-dioxane in the mixture is increased. The results indicate the presence of weak interactions between 1,4-dioxane and aromatic hydrocarbon molecules. The deviations in VmE values follow the order benzene less than toluene less than p-xylene less than m-xylene less than o-xylene less than mesitylene. It is observed that VmE values depend on the number and position of the methyl groups in these aromatic hydrocarbons.