Molecular interactions in binary mixtures of tetrahydrofuran with alkanols (C6,C8,C10):: An ultrasonic and volumetric study

The densities and ultrasonic speeds in binary mixtures of tetrahydrofuran (THF) with alkanols (1-hexanol, 1-octanol and 1-decanol) have been measured over the whole composition range at 35 degreesC. Isentropic compressibility, intermolecular free length, relative association, molecular association, acoustic impedance, excess compressibility, excess molar volume, excess acoustic impedance and excess partial molar volume of alkanols in THF were calculated using the values of density and ultrasonic speed. The variation of these parameters with composition indicates that the disruption of associated structure of alkanols on addition of THF dominates over that of weak interaction between unlike molecules in all the three systems investigated. Moreover, a comparison of theoretical ultrasonic speeds, calculated by using collision factor theory (CFT), free length theory (FLT), Nomoto's empirical relation and Van Dael-Vangeel's ideal mixing relation, with those obtained experimentally reveals that CFT, FLT and Nomoto's relation predict the data well than ideal mixing relation.