SOLUBILITY MEASUREMENTS OF HEMAMINECOBALT(III) TRIMETAPHOSPHATE IN AQUEOUS-SOLUTIONS OF DIFFERENT ELECTROLYTES

The solubility of Co(NH3)6P3O9 in water and in solutions of different electrolytes has been measured at 25.0°C. In the presence of inorganic cations, the increase in solubility is that predicted by a simple Debye-Hückel equation, with an å parameter of the order of 6.1 (uni-univalent electrolytes) or 4.8 (multivalent electrolytes) Å. Very small differences of such parameters account for the observed specific effects of inorganic electrolytes. The increase of solubility in the presence of slats with a common ion can be interpreted in the same way. The numerical Integration of the Poisson-Boltzmann Equation (IPBE) predicts the same results as well. The organic cations have a much smaller solubilizing effect, which does not appear to be related with the ion size only. © 1979.