Ultrasonic velocities (u), Densities (ρ) and Viscosities (η) have been measured experimentally at frequency of 2MHz and at constant temperature 303K for (1M Alanine + 1M NaCl) and (1M Alanine + 1M MgCl2). Using these experimental data, the thermodynamic properties i. e. adiabatic compressibility (β), intermolecular free length (Lf), acoustic impedance (z) and relative association (RA) have been computed. Excess thermodynamic parameters such as excess adiabatic compressibility (βE), excess intermolecular free length (Lf E), excess acoustic impedance (zE) and excess relative association (RA E) also have been calculated using standard relations. The results have been analyzed on the basis of variations in thermodynamic parameters as well as excess parameters. The variations in ultrasonic velocity and adiabatic compressibility with concentrations in both the systems show similar trends of increasing ultrasonic velocity and decreasing adiabatic compressibility of constituent electrolytes at 303K. This is due to complex formation and coordinate covalent bond form between the molecules of liquid solutions. Excess thermodynamic parameters i.e. excess adiabatic compressibility, excess intermolecular free length, excess acoustic impedance, and excess relative association elucidated the molecular interactions such as hydrogen bonding, ion – ion, ion – solvent, solute – solvent interactions in aqueous solutions and binary mixtures.
