IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


Glass Ball as Bullet Solubility System: Nickel formate with Zinc formate and Water

Components:
   (1) Nickel formate; Ni(CHO2)2; [3349-06-2]  NIST Chemistry WebBook for detail
   (2) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (3) Zinc formate; Zn(CHO2)2; [557-41-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Balarew, C.C.; Vassileva, V.Z., Compt. Rend. Acad. Bulg. Sci. 43, 51-4 (1990).

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 Ni(CHO2)2-Zn(CHO2)2-H2O system at 25 °C.
Chemical1PhaseMass Fraction w1m1 [mol kg-1]aChemical2Mass Fraction w2m2 [mol kg-1]aSolid Phase(s)bDistribution CoefficientZn2+/Ni2+Distribution CoefficientNi2+/Zn2+
Ni(CHO2)2Liquid2.140.146Zn(CHO2)2------A------
Ni(CHO2)2Liquid1.750.121Zn(CHO2)20.750.049B0.591.68
Ni(CHO2)2Liquid1.180.081Zn(CHO2)21.450.096B0.581.73
Ni(CHO2)2Liquid1.060.073Zn(CHO2)21.800.119B0.551.80
Ni(CHO2)2Liquid0.760.053Zn(CHO2)22.500.166B0.392.59
Ni(CHO2)2Liquid0.420.029Zn(CHO2)23.280.219B0.204.89
Ni(CHO2)2Liquid0.190.013Zn(CHO2)23.600.241B0.128.37
Ni(CHO2)2Liquid0.060.004Zn(CHO2)24.420.298B0.118.86
Ni(CHO2)2Liquid------Zn(CHO2)25.380.366C------
Notes:
   a  The molality values were calculated by the compilers.
   b  The solid phases are: A = Ni(CHO2)2•2H2O; B = (Ni,Zn)(CHO2)2•2H2O; C = Zn(CHO2)2•2H2O.

Method/Apparatus/Procedure:
   The method used was the isothermal decrease of supersaturation, for 15-20 hrs. The Ni2+ content of the liquid and solid phases was determined gravimetrically with dimethylglyoxime. The sum of Ni2+ and Zn2+ was determined complexometrically by back titration in excess of Complexon III with ZnSO4 at pH 5.5-6 using Xylenol Orange as indicator. The composition of the suction-dried mixed crystals was determined by the algebraic indirect identification of the solid phase composition method.1

Source and Purity of Materials:
   The reagents used were of p.a. grade. Nickel and zinc formates were prepared by the action of dilute formic acid with nickel and zinc carbonates, respectively.

Estimated Errors:
   Solubility: The solubility of the salts was determined in a slight excess of formic acid (about 2%) to suppress salt hydrolysis.
   Temperature: Not given.

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