Thermodynamic study of ternary (1-hexyl-3-methylimidazolium bromide + 2-ethoxyethanol + water) system based on conductometric and volumetric measurements

In this research, the molar conductivities and the apparent molar volume of 1-Hexyl-3 methylimidazolium bromide, [HMIm]Br, in the [HMIm]Br + 2-ethoxyethanol + water ternary system were reported using the conductometric and volumetric methods, respectively. The conductometric measurements were performed for [HMIm]Br from 0.0008 to 0.1671 mol.kg−1 in different mass fractions of 2-ethoxyethanol in 2-ethoxyethanol + water mixtures at T = (298.2, 308.2 and 318.2) K. Ion aggregation constants and limiting molar conductivities of [HMIm]Br were obtained using the Fuoss-Onsager equation and used to obtain the thermodynamic functions. In addition, volumetric measurements were performed to determine the apparent molar volume of [HMIm]Br in ternary system from 0.1003 to 0.4012 mol.kg−1 at T = (298.2, 308.2 and 318.2) K. Calculation of apparent molar volumes at infinite dilution, the infinite dilution apparent molar expansibility, and Hepler’s constant were performed using apparent molar volume values based on the Redlich-Mayer equation.