Ultrasonic Absorption and Excess Absorption Study of Polar and Non-Polar Binary Liquid Mixtures

Ultrasonic absorption&excess absorption study of binary liquid mixtures of polar solute acrylonitrile with non polar solvent cyclohexane and their binary liquid mixtures were carried out at 298 K in the frequency range 1MHz-10MHz and at different temperatures for 7 MHz over the entire range of composition. The observed ultrasonic absorption (α/f² obs), classical absorption (α/f² class), excess absorption (α/f² excess) and the ratio of the observed ultrasonic absorption (α/f² obs) and classical absorption (α/f² class) at different temperatures and at 7 MHz over the entire range of composition were studied. In this binary liquid mixture ultrasonic absorption is higher than the classical absorption. The thermo acoustical parameters acoustic impedance (Z), molecular weight (M), molar volume (V), molar sound velocity (R), molar compressibility (W), Vander Waal's constant (b), internal pressure (π _i), viscosity (η), intermolecular radius (r_o), relaxation time (τ), adiabatic compressibility (π_a), free volume (V_f), isothermal compressibility (β_i), intermolecular free length (L_f),etc were computed from ultrasonic velocities, densities and viscosities at 303 K and at frequency 7 MHz. Comparison of experimental ultrasonic velocity and it's theoretically calculated values by Junjie's relation, Impedance dependence relation and Nomoto's relation were studied. The increase in ultrasonic absorption with molar concentration is due to the possible structural relaxation process in the constituents. These structural relaxation processes play very important role in the study of molecular and structural properties of the constituent molecules in binary liquid mixture.