Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Densities and ultrasonic sound velocities have been measured over the whole composition range for the binary mixtures of tetrahydrofuran (THF) with 1,2-dichlorobenzene (1,2-DCB), 1,3-dichlorobenzene (1,3-DCB), 1,2,4-trichlorobenzene (1,2,4-TCB), o-chlorotoluene (o-CT), m-chlorotoluene (m-CT), p-chlorotoluene (p-CT), o-nitrotoluene (o-NT) and m-nitrotoluene (m-NT) at 298.15 K and atmospheric pressure. To gain some insight into the several aggregations of molecular interactions present in these mixed solvents, we determined the excess molar volume and the deviation in isentropic compressibilities as a function of the concentration of THF from the measured density and ultrasonic sound velocity, respectively. The excess molar volume values have been correlated using Redlich-Kister and Hwang et al. equations. The excess molar volume data is completely positive over the entire mole fraction range in all the binary mixtures of THF with chlorobenzenes, chlorotoluenes and nitrotoluenes. The sound velocity data have been obtained in terms of free length theory (FLT) and collision factor theory (CFT). The deviation in isentropic compressibility values have been correlated using Redlich-Kister equation. The values of deviation in isentropic compressibility were negative over the entire composition range in all the binary mixtures under the same experimental conditions. The measured data were discussed on the basis of intermolecular interactions and structural effects between unlike molecules. Based on our excess molar volume data of THF + DCBs or TCB and THF + chlorotoluenes are compared with existing excess molar volume data of THF + chlorobenzene (CB) and THF + toluene (TE), respectively.