IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


Glass Ball as Bullet Solubility System: Copper(II)formate with Formic acid and Water

Components:
   (1) Formic acid; CH2O2; [64-18-6]  NIST Chemistry WebBook for detail
   (2) Copper(II) formate; Cu(CHO2)2; [544-19-4]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Kalalova, E., Scientific papers of the Inst. Of Chem. Technol., Prague 9, 37 (1966).

Variables:
   Temperature = 0 ºC to 100 ºC

Prepared By:
   T. A. Ageyeva

Experimental Remarks:

   Transition points: Tetrahydrate to dihydrate is 317.7 ± 0.5 K. Dihydrate to anhydrous salt is 332 ± 1 K.

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
  
Solubility of copper(II)formate in 2% formic acid.
t/°CMass Fraction w1100 * Mole Fraction1aSolid Phase(s)b
    0  2.90.34A
  10  4.60.54A
  20  7.70.91A
  3013.21.54A
  4024.12.78A
  4529.53.39B
  5033.93.87B
  5848.55.45B
  6050.75.68C
  7049.15.51C
  8047.25.31C
  8547.85.37C
  9050.65.67C
10061.36.77C
Notes:
   a  These values were calculated by the compiler.
   b  The solid phases are: A = Cu(CHO2)2•4H2O; B = Cu(CHO2)2•2H2O; C = Cu(CHO2)2.

Method/Apparatus/Procedure:
   The isothermal method was used. Equilibrium was reached within 20 h. The copper content was measured by electrolytic deposition at a platinum cathode from a solution acidified with HNO3. The solid phase was identified by thermogravimetric and x-ray methods. Transition points between phases were determined thermogravimetrically. The solubility of each hydrate and the anhydrous salt were investigated.

Source and Purity of Materials:
   Cu(CHO2)2•4H2O was prepared by dissolving CuO in 50% formic acid followed by filtration and drying. Copper content was 28.16 mass % (calcd value is 28.16 mass %). The dihydrate was prepared by recrystallization of Cu(CHO2)2 in a thermostat at 323 K followed by filtration and drying at the same temperature. Copper content was 33.45 mass % (calcd value is 33.52 mass %). Anhydrous Cu(CHO2)2 was prepared from the dihydrate at 368 K. Copper content was 41.35 mass % (calcd value is 41.39 mass %). Source and purity of formic acid and water are not described.

Estimated Errors:
   Solubility: No information is given.
   Temperature: The temperature was controlled to within ±0.2 K. No other information is given.