Ultrasonic Study of Effect of Temperature and Concentration on Molecular Interaction in Ternary Liquid Mixture (Propylene Glycol + Benzene + Ethanol)

Abstract

Ultrasonic velocity, density and viscosity in the ternary mixture of propylene glycol, benzene and ethanol have been measured at 303, 308, 313 and 318 K and 2 MHz. The values of excess thermo-acoustic parameters uE, ηE, Ks E , Lf E , Vm E, ZE; and the Lennard-Jones potential repulsive term exponent (n) have been calculated by using the values of measured parameters. The variation in values and signs of excess parameters with increase in concentration of propylene glycol and temperature is explained by the mechanism of changing the nature of molecular interactions between unlike molecules. Further, the experimental ultrasonic velocities are compared with theoretical values calculated by using various theories like Nomoto′s relation (NR), Schaaffs′s collision factor theory (CFT) and Jacobson′s free length theory (FLT). The relative applicability of these theories is discussed in terms of average percentage errors (APE). The average percentage errors follows the order CFT < NR < FLT at each temperature.