Speeds of sound and isentropic compressibilities of (2-ethoxyethanol + ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol) binary mixtures at 298.15Â K

The speed of sound (u) has been obtained at a frequency of 8.3 MHz in {CH3CH2OCH2CH2OH + HOCH2CH2(OCH2CH2)nOH}for n = 0, 1, 2, and 3 over the whole composition range of studied binary liquid mixtures, at T = 298.15 K. The speed of sound values were combined with those of our previous results for densities and viscosities to obtain isentropic compressibility (κs), free volume (Vf), and intermolecular free length (Lf). From all these data excess isentropic compressibility (κsE), excess free volume (VfE) and excess intermolecular free length (LfE) as well as the deviations of the speed of sound (Δu) were obtained. The results are interpreted in terms of molecular interactions occurring in the solutions.