IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Copper(II) formate with Water

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

Original Measurements:
   Stoilova, D.; Balarew, C.; Vassileva, V., Comm. Dept. Chem. Bulg. Acad. Sci. 18, 3 (1985).

Variables:
   Temperature = 10 ºC to 70 ºC

Prepared By:
   Chr. Balarew and St. Trendafilova

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)

Solubility polytherm of copper formate in water.
t/°C	Phase	Mass Fraction w₁	m₁ [mol kg-1]^a	Solid Phase(s)^b
10	Liquid	5.58	0.385	A
15	Liquid	6.49	0.452	A
20	Liquid	7.03	0.492	A
25	Liquid	8.80	0.628	A
30	Liquid	11.06	0.810	A
35	Liquid	14.23	1.080	A
40	Liquid	18.52	1.480	A
45	Liquid	21.71	1.806	B
50	Liquid	25.17	2.190	B
55	Liquid	27.34	2.450	B
60	Liquid	27.48	2.467	C
65	Liquid	28.05	2.539	C
70	Liquid	28.50	2.595	C

Notes:
   ^a  These values were calculated by the compilers.
   ^b  The solid phases are: A = Cu(CHO₂)₂•4H₂O, B = Cu(CHO₂)₂•2H₂O, C = Cu(CHO₂)₂.

Method/Apparatus/Procedure:
   The method used was the isothermal decrease of supersaturation, under stirring, for 15-20 hrs. The Cu²⁺ content of the liquid and solid phases was determined complexometrically using Complexon III at pH 5.5-6.0 and Xylenol Orange as indicators.

Source and Purity of Materials:
   Analytical Reagent grade substances were used. The copper formate was obtained by neutralizing formic acid solutions with basic copper carbonate.

Estimated Errors:
   Solubility: The solubility of the salt is determined in a slight excess of formic acid (about 2%) to suppress salt hydrolysis.