J. N. Ramteke and S. B. Khasare
The ultrasonic velocity and related acoustical parameters are the important tools in understanding the nature and extent of pattern of molecular association resulting from intermolecular interactions between components of liquid mixture. These parameters have been used to understand different kinds of association, molecular packing and various types of intermolecular interactions and their strength of influence by the size of pure components and their mixture. Measurement of ultrasonic velocity gives the valuable information about the physico-chemical behavior of liquids and their mixtures. The theoretical evaluations of ultrasonic velocities in these pure liquids and binary liquid mixture and its comparison with measured values predict the extent of intermolecular interactions in the liquid mixture. The statistical and thermodynamic theories have been used to compute ultrasonic velocity in binary liquid mixture containing α- picoline in ethanol over the whole concentration range at 301.15K. Collision factor theory Nomato’s relation, Van Deel’s ideal mixing relation and Junji’s relation are used to compute theoretical ultrasonic velocities .These values are compared with the experimental values and their validity are checked by calculating the average percentage error. The agreement between theoretical and of experimental values was found to be satisfactory. Further, the molecular interaction parameter (α) was computed by using the values of experimental and theoretical ultrasonic velocities. The variations of this parameter with composition of mixture indicate the existence of molecular interactions in binary liquid mixture. The collision factory theory proposed by Shaft and Nutsch-Kuhnkies is found to best suited with experimental values having minimum percentage error over whole concentration range
