The study of solute-solvent interactions in 1-ethyl-3-methylimidazolium tetrafluoroborate+2-ethoxyethanol from density, speed of sound, and refractive index measurements

Physical properties, such as density (rho), speed of sound (u), and refractive index (n (D)) for pure [Emim][BF4], 2-ethoxyethanol and their binary mixtures, are measured using Anton Paar vibrating tube density and sound velocity meter (DSA 5000 M) and automatic refract meter over the whole composition range as a function of temperature between 298.15 and 328.15 K in steps of 10 K at atmospheric pressure. Experimental values were used to calculate the excess molar volumes (), excess values of partial molar volumes (), partial molar volumes at infinite dilution (), isentropic compressibility (), acoustic impedance (Z (E)), free length () and deviations in speeds of sound (u (d)), and refractive index () for the binary mixtures. These excess/deviation properties are fitted to the Redlich-Kister-type equation to obtain the binary coefficients and the standard errors. A qualitative analysis of intermolecular interactions between the liquids in study is analyzed on the basis of the measured and the derived properties.