硫酸亜鉛ならびに硫酸銅の低級アルコールおよびアセトン水溶液中の溶解度

抄録

Ternary equilibrium relations were established for zinc or copper sulfate-water-organic solvent system at 298K. Methyl-, isopropyl-, tert. butyl alcohol or acetone was used as an organic solvent.
The results are illustrated on the isothermal diagrams in Figures 2 to 5, and some of the numerical data are listed in Tables 1 and 2. Except of the case of methanol, the existence of miscibility gap was observed in ZnSO₄-H₂O-organic solvent system. The formation of two immiscible layers may be ascribed to the nature of the hydrophobic part of organic solvents. The existence of miscibility gap is not detected in CuSO₄-H₂O-organic solvent system, and the solubilities of copper sulfate decrease remarkably with increasing concentration of organic solvents as shown in Figures 6 and 7.
The difference of salting out effects with transition metal cations can be explained in terms of the standard Gibbs free energy of formation of aquo-metal cation. Dependence of the solubility on the dielectric constant of mixed solvent exhibits delicate variations by the cosolvent and its composition.
The experimental results were discussed and the applicability of data to industrial processes were examined.