Studies on molecular interaction in binary mixtures of diethyl ether with some alkanols – an acoustic approach

Abstract

The viscosity (η), density (ρ) and ultrasonic velocity (u) of pure diethyl ether (DEE) and three alkanols, namely methanol, n-propanol and n-butanol, and their binary mixture with DEE as a common component have been experimentally measured at 303.16 K under atmospheric pressure. The experimentally measured parameters were employed to compute the values of isentropic compressibility (β s), intermolecular free length (L f), molar volume (V m), acoustic impedance (Z), available volume (V a), free volume (V f), internal pressure (π i) and the viscous relaxation time (τ). Furthermore, the deviation functions such as were estimated in the entire range of DEE molefraction. The compositional variation of deviation functions were correlated to the Redlich–Kister-type polynomial equation. The sign and magnitude of deviation parameters have been interpreted in terms of H-bonding, proper interstitial accommodation in the structural process and the dipole–dipole type of molecular interactions between DEE and alkanol molecules. Theoretical values of ultrasonic velocity in all three binary mixtures have been estimated using five different empirical relations, such as Nomoto's relation, Junjie's relation, Rao's relation, Van Deal-Vageel's ideal mixing relation and impedance dependence relation. The relative merit of these relations with the measured values of ultrasonic velocity is discussed in this article.