Densities,Ultrasonic Speeds,Viscosities and Refractive Indices of Binary Mixtures of Benzene with Benzyl Alcohol,Benzonitrile, Benzoyl Chloride and Chlorobenzene at 303.15 K

Densities, ρ, ultrasonic speeds, u, viscosities, η , and refractive indices, n, of pure benzene, benzyl alcohol (BA), benzonitrile (BN), benzoyl chloride (BC), chlorobenzene (CB) and their thirty six binary mixtures, with benzene as common component, were measured at 303.15 K over the entire mole fraction range. From these experimental data the values of deviations in ultrasonic speed, Δu, isentropic compressibility, Δk_s, excess acoustic impedance, Z^E, deviation in viscosity, Δη, and excess Gibbs free energy of activation of viscous flow, G^*E, and partial molar isentropic compressibility, of BA, BN, BC and CB in benzene were computed. The variation of these derived functions with composition of the mixtures suggested the increased cohesion (molecular order) in the solution and that interaction (A‐B)>(A‐A) or (B‐B). Moreover, theoretical prediction of ultrasonic speed, viscosity and refractive index of all the four binary mixtures was made on the basis of empirical and semi‐empirical relations by using the experimental values of the pure components. Comparison of theoretical results with the experimental values was made in order to assess the suitability of these relations in reproducing the experimental values of u, η and n. Also, molecular radii of pure liquids and the average molecular radii of binary mixtures were evaluated using the corresponding refractive indices of pure liquids and binary mixtures. The average molecular radii of binary mixtures were found to be additive with respect to mole fraction of the pure component.