A Study of Ionic Equilibria in Solutions of Bi-Bivalent Electrolytes by Means of Solubility Measurements.

Section 1. The formation of complex ions of manganese oxalate in the presence of soluble oxalates was studied by means of solubility measurements. The manganese oxalate (dihydrate) being prepared, and the analytical procedure being worked out. The dissociation constant for the auto-complex formation was obtained, and the previously reported value for the primary dissociation constant corrected. Section 2. Barium oxalate (dihydrate) was prepared and a series of solubility measurements made, using uniunivalent and uni-bivalent electrolytes. The activities were studied by means of the Debye-Huckel and Bronsted equations, and it was found that better agreement with the theoretical requirements was obtained when allowance was made for incomplete dissociaton, than when the salts were considered completely dissociated. This was particularly marked in the case of uni-bivalent electrolytes (manganese and magnesium chlorides). The dissociation constants for the latter salts were indirectly determined and found to agree fairly well with the previously obtained values. It was shown that barium oxalate shows no tendency to auto-complex formation in the presence of soluble oxalates. Section 3. The available data for the solubility of barium bromate in salt solutions was studied, and in this case also, better agreement with the theoretical requirements was obtained when allowance was made for incomplete dissociation. Section 4. A previously published paper : Money and Davies. Trans. Far. Soc. 28. 609. 1932. The dissociation constants of some bi-bivalent salts in water were calculated from conductivity measurements