Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Thermodynamic properties of ionic liquid, 1-ethyl-3-methylimidazolium hydrogen sulfate ([Emim] [HSO4]) in lithium chloride (LiCl) aqueous solutions have been investigated. Osmotic and activity coefficients of the ternary system ([Emim][HSO4] + LiCl + H2O) and their corresponding binary mixtures at T = 298.15 K are evaluated using isopiestic method. Using these data, the vapor pressures for these systems are determined. For binary systems, the Pitzer, Pitzer-Archer and modified-Pitzer models are satisfactorily correlated to the osmotic coefficients data. The Scatchard neutral-electrolyte model is fitted to the osmotic coefficients for ternary systems and corresponding mean activity coefficients for the binary and ternary systems are appraised. The densities of the ternary system ([Emim][HSO4] + LiCl + H2O) are measured at T = (293.15 313.15) K using a vibrating U-tube densimeter. Based on experimental density data, the apparent molar volumes, Vu, are computed. The equation that reported in Redlich-Meyer article was used to correlate the Vu values and apparent molar volumes at infinite dilution, Vu 0, are also calculated. Our results showed a negative transfer volume of [Emim][HSO4] from water to the aqueous (LiCl) solution which decreases by enhancing the (LiCl) mass fraction and temperature. The solute solvent interactions and structure making or breaking ability of 1-ethyl-3-methylimidazolium hydrogen sulfate have been discussed in details.