IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


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

Components:
   (1) Cadmium formate; Cd(CHO2)2; [4464-23-7]  NIST Chemistry WebBook for detail
   (2) Sodium formate; NaCHO2; [141-53-7]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Itkina, L.S.; Nadzharyan, K.A., Zh. Neorg. Khim. 26, 515 (1981).

Variables:

   Concentration = Composition at 50 ºC

Prepared By:
   Chr. Balarew and St. Trendafilova

Experimental Remarks:

   The molality values were calculated by the compilers.

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
  
Solubility values in the NaCHO2-Cd(CHO2)2-H2O system at 50 °C.
Chemical1PhaseMass Fraction w1m1 [mol kg-1]Chemical2Mass Fraction w2m2 [mol kg-1]Solid Phase(s)a
NaCHO2Liquid49.9714.69Cd(CHO2)2------A
NaCHO2Liquid50.3815.50Cd(CHO2)21.830.189A+B
NaCHO2Liquid45.5312.73Cd(CHO2)21.890.178B
NaCHO2Liquid42.2611.14Cd(CHO2)21.920.175B
NaCHO2Liquid37.679.176Cd(CHO2)21.970.161B
NaCHO2Liquid33.237.597Cd(CHO2)22.200.169B
NaCHO2Liquid24.454.933Cd(CHO2)22.680.182B
NaCHO2Liquid13.032.507Cd(CHO2)210.570.683B
NaCHO2Liquid9.761.94Cd(CHO2)216.151.077B
NaCHO2Liquid8.051.76Cd(CHO2)224.831.827B+C
NaCHO2Liquid7.501.62Cd(CHO2)224.471.777C
NaCHO2Liquid4.580.948Cd(CHO2)224.381.695C
NaCHO2Liquid--Cd(CHO2)227.771.899C
Notes:
   a  The solid phases are: A = NaCHO2; B = NaCd(CHO2)3; C = Cd(CHO2)2•2H2O.

Method/Apparatus/Procedure:
   The isothermal method was used. Equilibrium was reached in 2.5 weeks. The sodium content of both phases was determined by flame photometry. The Cd2+ content was determined complexometrically using Eriochrome Black T as the indicator. The composition of the solid phases was determined by Schreinemakers' method, by TG analysis, IR spectroscopy and x-ray diffraction.

Source and Purity of Materials:
   NaCHO2 and Cd(CHO2)2•2H2O were prepared by reacting formic acid with p.a. grade NaOH and CdCO3, respectively. The sodium formate synthesis was carried out in an alkaline medium to prevent formation of the acid salt.

Estimated Errors:

   Temperature: The temperature was kept constant to within ± 0.1 °C.