ULTRASONIC INVESTIGATION OF BIO-LIQUID MIXTURES OF METHANOL WITH CINNAMALDEHYDE BY INTERFEROMETRIC METHOD OPERATED IN THE FREQUENCY RANGE 1 MHZ-10 MHZ

O. P. Chimankar, N. R. Pawar

Abstract: Ultrasonic absorption study of binary liquid mixtures of cinnamaldehyde with polar solvent methanol and their binary liquid mixture were carried out at 298 K in the frequency range 1MHz-10MHz and at five different temperatures 293 K, 298 K, 303 K, 308 K and 313 K for 7 MHz over the entire range of composition. The observed ultrasonic absorption (a/f2 obs), classical absorption (a/f2 class), excess absorption (a/f2 excess) and the ratio of the observed ultrasonic absorption (a/f2 obs) and classical absorption (a/f2 class) in the temperature range 293 K, 298 K, 303 K, 308 K and 313 K and at 7 MHz over the entire range of composition and their variation with compositions were studied. In this binary system it is observed that ultrasonic absorption is higher than the classical absorption. It is a characteristic feature of this binary liquid mixture. 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 (pi), viscosity (?), intermolecular radius (ro), relaxation time (t), adiabatic compressibility (ßa), free volume (Vf), isothermal compressibility (ßi) , intermolecular free length (Lf ),etc were computed for the all the binary systems 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 increase in molar concentration is due to the possible structural relaxation process in this binary system. These structural relaxation processes play very important role in the study of molecular and structural properties of the component molecules in binary liquid mixture.

Keywords: Ultrasonic velocity, absorption, compressibility, relaxation time, acoustic impedance, Vander wall’s constant, adiabatic compressibility (ßa), internal pressure (pi), relaxation time (t), free length (Lf ), methanol and cinnamaldehyde.

DOI: https://doi.org/10.15623/ijret.2014.0306059