Experimental study of the excess properties for (1,2-Dichloroethane or Dichloromethane with N,N-Dimethyl formamide or Dimethyl sulfoxide) at 308.15Â K

Ultrasonic velocities, u, and densities, ρ, of binary mixtures of 1,2-Dichloroethane + N,N-Dimethyl formamide, 1,2-Dichloroethane + Dimethyl sulfoxide, Dichloromethane + N,N-Dimethyl formamide and Dichloromethane + Dimethyl sulfoxide including pure liquids, over the entire composition range have been measured at 308.15 K. Using the experimental results, deviation in ultrasonic velocity, Δu, deviation in isentropic compressibility, Δks, excess intermolecular free length, LfE, excess acoustic impedance, zE, deviation in isothermal compressibility, ΔβT and deviation in thermal expansion coefficient, Δα, have been calculated. The excess values of some of the above parameters have also been evaluated and fitted to the Redlich-Kister polynomials and the results are interpreted in terms of molecular interactions present in the mixtures. Using the calculated data, molar compressibility, partial molar compressibility and excess partial molar compressibility were also evaluated for all the investigated binary mixtures.