IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


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

Components:
   (1) Copper formate; Cu(CHO2)2; [544-19-4]  NIST Chemistry WebBook for detail
   (2) Nickel formate; Ni(CHO2)2; [3349-06-2]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Stoilova, D.; Risova, D. Bulg. Chem. Commun. 26, 268-273 (1993).

Variables:

   Concentration = Composition at 50 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-Cu(CHO2)2-H2O system at 50 °C.
Chemical1PhaseMass Fraction w1m1 [mol kg-1]aChemical2Mass Fraction w2m2 [mol kg-1]aSolid Phase(s)bDistribution CoefficientNi2+/Cu2+Distribution CoefficientCu2+/Ni2+
Cu(CHO2)2Liquid25.172.190Ni(CHO2)20.000.00A------
Cu(CHO2)2Liquid25.032.207Ni(CHO2)21.150.105B0.721.39
Cu(CHO2)2Liquid24.952.218Ni(CHO2)21.810.166B2.040.49
Cu(CHO2)2Liquid22.801.975Ni(CHO2)22.040.184B3.880.26
Cu(CHO2)2Liquid22.541.944Ni(CHO2)21.970.175B4.570.22
Cu(CHO2)2Liquid20.191.749Ni(CHO2)21.620.145eutonic
Cu(CHO2)2Liquid20.101.675Ni(CHO2)21.790.154eutonic
Cu(CHO2)2Liquid20.631.723Ni(CHO2)21.420.122eutonic
Cu(CHO2)2Liquid17.141.377Ni(CHO2)21.810.150C9.100.11
Cu(CHO2)2Liquid12.740.974Ni(CHO2)22.120.167C9.100.11
Cu(CHO2)2Liquid9.690.714Ni(CHO2)21.910.145C11.760.09
Cu(CHO2)2Liquid6.320.448Ni(CHO2)21.760.129C11.100.09
Cu(CHO2)2Liquid4.190.292Ni(CHO2)22.320.167C7.690.13
Cu(CHO2)2Liquid2.120.146Ni(CHO2)23.310.235C5.550.18
Cu(CHO2)2Liquid0.000.00Ni(CHO2)22.780.192D------
Notes:
   a  The molality values were calculated by the compilers.
   b  The solid phases are: A = Cu(CHO2)2•2H2O; B = (Cu,Ni)(CHO2)2•2H2O; C = (Ni,Cu)(CHO2)2•2H2O; D = Ni(CHO2)2•2H2O.

Method/Apparatus/Procedure:
   The solubility was studied by the method of isothermal decrease of supersaturation. The equilibrium was reached in about two days. The liquid phase concentrations were determined as follows: the sum of the copper and cobalt formate concentrations was determined complexometrically at pH 5.5-6.0 using Xylenol orange as indicator, the copper formate concentration was determined iodometrically. The cobalt formate concentration was estimated by difference. The variation of the Schreinemakers method was used for calculation of ideally suction dried solid phase composition.1 X-ray powder analysis and IR spectra were carried out.

Source and Purity of Materials:
   The metal formates were prepared from reaction of the corresponding metal hydroxide carbonates with dilute formic acid solutions at 70-80 °C. The crystals were recrystallized in water and dried in air. The reagents used were p.a.(Merck).

Estimated Errors:
   Solubility: The experiments were carried out in presence of a slight excess of formic acid (1-2 mass %) in order to suppress the salt hydrolysis.
   Temperature: Not given.

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