Collect. Czech. Chem. Commun. 2001, 66, 89-98

Ionic Processes in Saturated Solutions of MgCl2·6H2O in Solutions of Other Divalent Metals

Jitka Eysseltová

Department of Inorganic Chemistry, Charles University, 128 40 Prague 2, Czech Republic


Solubility isotherms of MgCl2·6H2O at 25 °C in solutions of chlorides of bivalent beryllium, calcium, manganese, iron, cobalt, zinc and mercury were treated by the hydration analysis. In addition to the usual procedure, the recently developed modified transfer energy Ξ was used to characterize the situation in saturated solutions. As a result, the following ionic processes were established in the saturated solutions under consideration: competition for water in solutions of MgCl2·6H2O containing beryllium and calcium chloride, complex formation in solutions of MgCl2·6H2O containing manganese, cobalt, zinc and mercury ions and formation of ions with heterogeneous coordination sphere in solutions of MgCl2·6H2O containing iron or copper ions. In the last case, the ability of the formed ions to crystallize from solution was found to be reduced in comparison with the other cases. Activity coefficients of MgCl2 were calculated along the solubility curves under consideration.

Keywords: Solubility; Aqueous solutions; Hydration analysis; Activity coefficients; Magnesium chloride hexahydrate; Divalent metal chlorides; Crystallization.

References: 15 live references.