Abstract: Sound velocity, density, and viscosity values were measured at 303Kin four binary systems of benzene + 1-, 2-, tert-, or iso-butanol. From these data, acoustical parameters, such as adiabatic compressibility, free length, free volume, and internal pressure were estimated using the standard relations. The results are interpreted in terms of molecular interaction between the components of the mixtures. Observed excess value in all the mixture indicates that the molecular symmetry existing in the system is highly disturbed by the nonpolar benzene molecules. Interaction energy terms of the statistical mixing are also verified for these binary systems and the dipole-dipole interactions are found to be predominantly present and are sharply affected by the isomeric forms of butanol.

Key words: Ultrasonic velocity, Acoustic parameter, Dipolar interaction, Interaction