The ultrasonic velocity, density and viscosity have been measured for the binary mixtures of some of the aromatic hydrocarbons such as toluene, benzene, and chlorobenzene with dimethylsulphoxide (DMSO) at 303.15K. The experimental data have been used to calculate the acoustical parameters namely adiabatic compressibility (b), free length (Lf), free volume (Vf), internal pressure (pi), and acoustic impedance (Z). The excess values of some the above parameters are also evaluated and discussed in the light of molecular interaction in the mixtures. It is eventually concluded that a weak molecular interaction is noticed. Such interactions are primarily due to weak dipole-dipole or dipole-induced dipolar forces. Among the three liquid systems studied, the molecular interactions are more pronounced in System-II and less pronounced in System-III.
