
Ultrasonic velocity, viscosity and density studies on solution of tetrabutylammonium iodide (Bu4NI) in Dimethylsulphoxide (DMSO) and Dimethylsulphoxide + Acetone solvent mixtures containing 50,60,70,80,90 and 100 mol % of DMSO at 298 and 308K have been reported. From the velocity, viscosity and density data values, various parameters namely, the adiabatic compressibility (β), apparent molar compressibility (ϕk), apparent molar volume (ϕv), limiting apparent molar compressibility (ϕko), limiting apparent molar volume (ϕvo), free volume (Vf), internal pressure (πi), relaxation time (τ) and viscosity B-coefficient have been calculated. All these parameters have been discussed separately to throw light on the solute-solvent and solvent-solvent interactions.