Components:
(1) Lithium formate,
LiCHO2; [556-63-8]
NIST WebBook
(2) Cobalt formate,
Co(CHO2)2; [544-18-3]
NIST WebBook
(3) Water,
H2O; [7732-18-5]
NIST WebBook
Original Measurements
Ahmatova, Zh. T.; Borina, A. F.; Lyashchenko, A. K.; Portnova, S. M.; Zh. Neorg. Khim. 31, 237-42 (1986).
Variables:
Ambient temperature: Composition at 25 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
The isothermal method was used. Three weeks were allowed for equilibration. The lithium content of both phases was determined by flame photometry. The cobalt content was determined complexometrically by back titration with ZnSO4 at pH 5.5-6.0 using Xylenol Orange as indicator. The composition of the solid phases was determined by Schreinemakers' method.
Source and Purity of Materials:
- The lithium formate was obtained by recrystallizing "pro analysis" LiCHO2·H2O. Cobalt formate dihydrate was prepared by treating p.a. cobalt nitrate with KOH to ppt the hydroxide and then dissolving the hydroxide in a formic acid solution.
Estimated Errors:
Ambient temperature: No information is given.
Mass concentration (m/v) (1): No information is given.
Experimental Values:
Solubility values in the LiCHO2-Co(CHO2)2-H2O system at 25°C.
| 100w1 | 100w2 | m1 (mol/kg)b | m2 (mol/kg)b | Phase (s)a |
|---|---|---|---|---|
| - | 2.42 | - | 1.66 x 10-1 | A |
| 2.47 | 1.44 | 4.95 x 10-1 | 1.01 x 10-1 | A |
| 6.14 | 5.3 x 10-1 | 1.27 | 3.8 x 10-2 | A |
| 8.83 | 3.7 x 10-1 | 1.87 | 2.7 x 10-2 | A |
| 13.1 | 2.8 x 10-1 | 2.911 | 2.2 x 10-2 | A |
| 16.99 | 2.3 x 10-1 | 3.95 | 1.8 x 10-2 | A |
| 20.21 | 2.2 x 10-1 | 4.888 | 1.8 x 10-2 | A |
| 22.16 | 2.2 x 10-1 | 5.495 | 1.9 x 10-2 | A |
| 22.98 | 2.3 x 10-1 | 5.76 | 2.0 x 10-2 | A |
| 24.78 | 3.7 x 10-1 | 6.372 | 3.3 x 10-2 | A + B |
| 25.0 | 4.1 x 10-1 | 6.451 | 3.7 x 10-2 | A + B |
| 26.8 | 2.2 x 10-1 | 7.068 | 2.0 x 10-2 | B |
| 27.47 | 2.0 x 10-1 | 7.31 | 1.8 x 10-2 | B |
| 27.56 | 2.7 x 10-1 | 7.35 | 2.5 x 10-2 | B |
| 28.02 | 1.5 x 10-1 | 7.508 | 1.4 x 10-2 | B |
| 27.85 | - | 7.429 | - | B |
(a) The solid phases are: A = Co(CHO2)2·2H2O ; B = LiCHO2·H2O. (b) The molality values were calculated by the compilers.
