Volumetric and acoustic studies on (tetraethylene glycol + water) mixtures in a wide temperature range

The sound velocity (u) and density (ρ) of (tetraethylene glycol (T4EG) + water) mixtures were measured in the whole mixture composition range. Density measurements were carried out in the temperature range of (278.15 to 333.15) K, while acoustic measurements in the temperature range of (288.15 to 318.15) K. Density and sound velocity values were used to determine the values of molar volume (Vm), adiabatic compressibility coefficient (βs) as well as temperature coefficients of these parameters. The values of excess compressibility coefficient (βsE), excess molar volume (VmE), excess expansion volume coefficient (αE) and derivatives (∂H/∂p), (∂S/∂p) and (∂Cp/∂p) were also determined. The partial molar volumes of the mixture components were calculated. Changes in the measured and calculated values of physicochemical parameters as functions of composition and temperature were analysed in terms of interactions and structure of the binary mixtures investigated.