Densities and ultrasonic studies for binary mixtures of tetrahydrofuran with chlorobenzenes, chlorotoluenes and nitrotoluenes at 298.15 K

Densities (ρ) and ultrasonic sound velocities (u) 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 (VE) and the deviation in isentropic compressibilities (Δκs) as a function of the concentration of THF from the measured ρ and u, respectively. The VE values have been correlated using Redlich–Kister and Hwang et al. equations. The VE 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 Δκs values have been correlated using Redlich–Kister equation. The values of Δκs 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 VE data of THF + DCBs or TCB and THF + chlorotoluenes are compared with existing VE data of THF + chlorobenzene (CB) and THF + toluene (TE), respectively.