IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


Glass Ball as Bullet Solubility System: Manganese formate with Cadmium formate and Water

Components:
   (1) Cadmium formate; Cd(CHO2)2; [4464-23-7]  NIST Chemistry WebBook for detail
   (2) Manganese formate; Mn(CHO2)2; [3251-96-5]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Balarew, C.; Stoilova, D.G.; Vassileva, V.Z., Dokl. Bolg. Acad. Nauk 35, 933 (1982).

Variables:

   Concentration = Composition at 25 ºC

Prepared By:
   Chr. Balarew and St. Trendafilova

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
  
Solubility values in the Mn(CHO2)2-Cd(CHO2)2-H2O system at 25 °C.
Chemical1PhaseMass Fraction w1m1 [mol kg-1]aChemical2Mass Fraction w2m2 [mol kg-1]aSolid Phase(s)bDistribution CoefficientCd2+/Mn2+Distribution CoefficientMn2+/Cd2+
Mn(CHO2)2Liquid6.280.462Cd(CHO2)2------A------
Mn(CHO2)2Liquid5.830.433Cd(CHO2)21.220.065B0.631.59
Mn(CHO2)2Liquid5.590.418Cd(CHO2)22.170.116B0.841.19
Mn(CHO2)2Liquid5.050.380Cd(CHO2)23.210.173B1.001.00
Mn(CHO2)2Liquid4.730.356Cd(CHO2)23.570.192B0.921.09
Mn(CHO2)2Liquid3.710.283Cd(CHO2)26.000.328B0.871.15
Mn(CHO2)2Liquid2.590.201Cd(CHO2)28.350.463B0.861.16
Mn(CHO2)2Liquid2.190.170Cd(CHO2)29.010.501B0.941.06
Mn(CHO2)2Liquid1.150.090Cd(CHO2)210.960.616B0.791.27
Mn(CHO2)2Liquid0.000.00Cd(CHO2)212.450.703C------
Notes:
   a  The molality values were calculated by the compilers.
   b  The solid phases are: A = Mn(CHO2)2•2H2O; B = (Mn,Cd)(CHO2)2•2H2O; C = Cd(CHO2)2•2H2O.

Method/Apparatus/Procedure:
   Equilibrium was reached after about 2 days of stirring using the isothermal decrease of supersaturation method. The sum of the Mn2+ and Cd2+ content of both phases was determined complexometrically with Complexon III at pH 9.5-10, using Eriochrome Black T as indicator after adding hydroxylamine hydrochloride. Mn2+ in the presence of Cd2+ was determined the same way after binding the Cd2+ as cyanide complexes. The composition of the suction-dried mixed crystals was determined by the method of algebraic indirect identification of the solid phase. 1

Source and Purity of Materials:
   The manganese and cadmium formates were prepared by the reaction of dilute formic acid with manganese and cadmium carbonates, respectively. All reagents were p.a. grade.

Estimated Errors:
   Solubility: The solubilities were determined in a slight excess of formic acid (about 2%) in order to inhibit hydrolysis.
   Temperature: Not given.

References:
   1D. Trendafelov and Chr. Balarew, Comm. Dept. Chem. Bulg. Acad. Sci. 1, 73 (1968).