The study of vapor–liquid equilibria of 1-ethyl-3-methyl imidazolium chloride and 1-butyl-3-methyl imidazolium chloride in lithium bromide aqueous solutions and their corresponding binary systems at 298.15 K.

Osmotic and activity coefficient of mixed aqueous solutions, 1-ethyl-3-methyl imidazolium chloride (EmimCl) and 1-butyl-3-methyl imidazolium chloride (BmimCl) in lithium bromide and their corresponding binary aqueous solutions have been measured by the isopiestic method at a 298.15 K. From the obtained osmotic coefficient data vapor pressure values have also been determined for the ternary (EmimCl+LiBr+H2O) and (BmimCl+LiBr+H2O) and corresponding binary aqueous EmimCl, BmimCl and LiBr solutions. The osmotic coefficients for binary aqueous solutions were correlated to the Pitzer, Pitzer–Archer and TCPC models. From these data, the corresponding mean activity coefficient, γ ± have been calculated. The activity coefficients of mixed electrolytes were calculated by Scatchardʹs neutral-electrolyte method.