Components:
(1) Copper formate,
Cu(CHO2)2; [544-19-4]
NIST WebBook
(2) Formic acid,
CH2O2; [64-18-6]
NIST WebBook
(3) Water,
H2O; [7732-18-5]
NIST WebBook
Original Measurements
Kalalova, E.; Scientific papers of the Inst. Of Chem. Technol.; Prague 9, 37 (1966).
Variables:
Ambient temperature: 0 - 100 °C
Prepared by:
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:
Ambient temperature: The temperature was controlled to within ±0.2 K. No other information is given.
Mass concentration (m/v) (1): No information is given.
Experimental Values:
Note: Transition points: Tetrahydrate to dihydrate is 317.7 ± 0.5 K. Dihydrate to anhydrous salt is 332 ± 1 K.Solubility of copper(II)formate in 2% formic acid.
| T (°C) | g1/100 g sln2+3 | 100x1 | Phase (s)b |
|---|---|---|---|
| 0.0 | 2.9 | 3.4 x 10-1 | A |
| 10.0 | 4.6 | 5.4 x 10-1 | A |
| 20.0 | 7.7 | 9.1 x 10-1 | A |
| 30.0 | 13.2 | 1.54 | A |
| 40.0 | 24.1 | 2.78 | A |
| 45.0 | 29.5 | 3.39 | B |
| 50.0 | 33.9 | 3.87 | B |
| 58.0 | 48.5 | 5.45 | B |
| 60.0 | 50.7 | 5.68 | C |
| 70.0 | 49.1 | 5.51 | C |
| 80.0 | 47.2 | 5.31 | C |
| 85.0 | 47.8 | 5.37 | C |
| 90.0 | 50.6 | 5.67 | C |
| 100.0 | 61.3 | 6.77 | C |
(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.
