Osmotic and activity coefficient of 1-ethyl-3-methylimidazolium chloride in aqueous solutions of tri-potassium phosphate, potassium carbonate, and potassium chloride at T=298.15K

Vapour–liquid equilibrium data (water activity, vapour pressure, osmotic coefficient, and activity coefficient) of the mixed electrolyte aqueous solutions, 1-ethyl-3-methylimidazolium chloride, (EmimCl) + tri-potassium phosphate, EmimCl + potassium carbonate, EmimCl + potassium chloride and their corresponding binary aqueous solutions have been measured by the isopiestic method at a temperature of 298.15 K. The osmotic coefficients for binary aqueous solutions were correlated to the Pitzer, modified Pitzer and TCPC models. The osmotic coefficient of mixed electrolyte with common anion was correlated to the Pitzer model. From these data, the corresponding mean activity coefficients, γ±γ±, have been calculated. The activity coefficients of mixed electrolytes were calculated by Scatchard’s neutral electrolyte method. A modified Pitzer model has been used to predict the osmotic and activity coefficients of mixed electrolyte solution with common anion.

► We measured water activity data for 1-ethyl-3-methylimidazolium chloride+salts+H2O.
► The isopiestic method is used at 298.15 K and the salts are K3PO4, K2CO3 and KCl.
► Osmotic coefficients for binary solutions were fitted with Pitzer, and TCPC models.
► Activity coefficients of mixed electrolytes were calculated by Scatchard’s method.
► Activity coefficients for ionic liquid+KCl+H2O were predicted with modified Pitzer.