Components:
(1) Cobalt formate,
Co(CHO2)2; [544-18-3]
NIST WebBook
(2) Yttrium(III) formate,
Y(CHO2)3; [15331-71-2]
NIST WebBook
(3) Water,
H2O; [7732-18-5]
NIST WebBook
Original Measurements
Portnova, S. M.; Krassilov, Yu. I.; Kuznetzov, N. T.; Balakaeva, I. V.; Zh. Neorg. Khim. 35, 237-41 (1990).
Variables:
Ambient temperature: Composition at 25 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
The isothermal method was used. One month was allowed for equilibration. The Y3+ and Co2+ contents were determined complexometrically using diethyldithiocarbamate.1 The composition of the solid phases was determined by the Schreinemakers method.
Source and Purity of Materials:
- The formates were obtained by neutralizing dilute formic acid with p.a. grade Y(OH)3 and basic cobalt carbonate.
Estimated Errors:
Ambient temperature: No information given.
Mass concentration (m/v) (1): No information given.
References
1 Fritz, J. S.; Oliver, R. T.; Pietryc, D. L.; Anal. Chem. 30, 1111 (1958).
Experimental Values:
Solubility values in the Co(CHO2)2-Y(CHO2)3-H2O system at 25°C.
| 100w1 | 100w2 | m1 (mol/kg)a | m2 (mol/kg)b | Phase (s)b |
|---|---|---|---|---|
| 2.42 | - | 1.66 x 10-1 | - | A |
| 1.53 | 3.58 | 1.08 x 10-1 | 1.68 x 10-1 | A |
| 1.13 | 8.65 | 8.4 x 10-2 | 4.28 x 10-1 | A |
| 8.6 x 10-1 | 9.19 | 6.4 x 10-2 | 4.56 x 10-1 | A |
| 6.5 x 10-1 | 15.74 | 5.2 x 10-2 | 8.41 x 10-1 | A |
| 6.7 x 10-1 | 19.98 | 5.7 x 10-2 | 1.124 | A + B |
| 5.3 x 10-1 | 20.14 | 4.5 x 10-2 | 1.134 | B |
| - | 21.41 | - | 1.216 | B |
(a) The molality values were calculated by the compilers. (b) The solid phases are: A = Co(CHO2)2·2H2O; B = Y(CHO2)3·2H2O.
