thermodynamics of ion association in the saturated solution of the mixed solvent (methanol+water) and ion pairing at 25.0°c

in this study, the ion association phenomenon in the saturated solution of kcl in the mixed solvent(methanol+water) was studied. the solubility of this compound in the mixed solvent (methanol+water by value percent of methanol = 60%), and in the presence of various molarities of nano3 wasdetermined by the solvent evaporation method at 25.0°c. the results enable us to estimate the valueof thermodynamic solubility product, ksp(th), of kcl in the mixed solvent upon the extrapolationmethod (ksp(th) = 0.1356). although the model solubility product, ksp(m), was calculated upon the semitheoretical semi experimental debey-huckle theory shows (ksp(m) = 0.2308 ). comparing the valuesof ksp(th) and ksp(m) with the concentration solubility product, (ksp(c) = 0.5537), we can see that thedifferences are noticeable.we assume that, part of the differences comes from non-ideality and the other part from ionassociation phenomenon.