Excess molar volumes and speeds of sound of tetrahydrofuran with chloroethanes or chloroethenes at 298.15 K

Abstract

Excess molar volumes, and speeds of sound, u of the binary liquid mixtures of tetrahydrofuran (THF) with chloroethanes or chlororethenes at 298.15 K have been measured over the entire range of (THF) compositions. The chloroethanes are 1,2-dichloroethane, 1,1,1-trichloroethane, and 1,1,2,2-tetrachloroethane and the chloroethenes are trichloroethylene and tetrachloroethylene. Partial molar volumes , were also calculated and their values have been extrapolated to zero concentration to obtain the limiting values at infinite dilution, . The values are negative in mixtures of THF + tetrachloroethylene, + trichloroethylene, + 1,1, 1-trichloroethane, and + 1,1,2,2-tetrachloroethane over the entire composition range of THF. The values are positive for THF with 1,2-dichloroethane. An inversion of the sign of was observed at x ≈ 0.75 of THF for the mixtures of THF with 1,2-dichloroethane. Further, isentropic compressibilities, k s of the mixtures were computed by combining speeds of sound and density data. Deviation in isentropic compressibility, Δk s were evaluated using volume fraction ϕ weighing of the individual component properties to estimate ideal mixture behaviour. The Δk s values are negative over the whole of volume fraction for all the mixtures except for 1,2-dichloroethane. The Δk s values were positive over the entire volume fraction of THF with 1,2-dichloroethane. For all systems, and Δk s values were satisfactorily correlated by the Redlich–Kister polynomial. The results are explained in terms of dissociation of the self-associated chloroethanes or chloroethene molecules and the formation of aggregates between unlike molecules.