SDS Volume (4676)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Eremeeva, I. L.; Kalacheva, V. G.; Schwartz, E. M.; Zh. Neorg. Khim. 22, 861-2 (1977).
Variables:
Room Temp: Composition at 25 °C
Prepared by:
St. Trendafilova, St. Tepavitcharova
Method/Apparatus/Procedure:
The isothermal method was used. Equilibrium was established when a constant pH, diffraction coefficient and concentration of $\ce{H3BO3}$ were reached. The $\ce{Ca^{2+}}$ and $\ce{B^{3+}}$ contents were determined as $\ce{CaO}$ and $\ce{B2O3}$. The composition of the solid phases was determined by the Schreinemakers method.
Source and Purity of Materials:
- $\ce{Ca(CHO2)2}$ was prepared by reaction of $\ce{CaCO3}$ with C$\ce{H2O2}$. The product was recrystallized twice. Suprapure grade boric acid was used.
Estimated Errors:
Ambient temperature: ±0.02°C.
Components:
- Calcium formate, $\ce{ Ca(CHO2)2 }$; [544-17-2] NIST WebBook
- Boric acid, $\ce{ H3BO3 }$; [10043-35-3] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility values in the Ca(CHO2)2-H3BO3-H2O system at 25°C.
| 100w1 | 100w2 | m1 (mol/kg) | m2 (mol/kg) | Phase (s) () |
|---|---|---|---|---|
| 14.43 | 0.0 | 1.30 | 0.0 | A |
| 14.30 | 1.46 | 1.30 | 0.28 | A |
| 13.98 | 2.60 | 1.29 | 0.50 | A |
| 13.80 | 3.09 | 1.28 | 0.60 | A |
| 13.70 | 4.46 | 1.29 | 0.88 | A |
| 13.90 | 4.40 | 1.31 | 0.87 | A |
| 13.94 | 4.61 | 1.32 | 0.92 | A |
| 13.80 | 5.25 | 1.31 | 1.05 | A |
| 13.5 | 5.75 | 1.28 | 1.15 | A + B |
| 12.80 | 5.65 | 1.21 | 1.12 | B |
| 11.0 | 5.64 | 1.01 | 1.00 | B |
| 10.0 | 5.59 | 0.91 | 1.07 | B |
| 7.22 | 5.58 | 0.64 | 1.03 | B |
| 6.40 | 5.53 | 0.56 | 1.02 | B |
| 3.70 | 5.48 | 0.31 | 0.98 | B |
| 1.60 | 5.52 | 0.13 | 0.96 | B |
| 0.0 | 5.51 | 0.0 | 0.94 | B |
(a) The molality values were calculated by the compilers.
(b) The solid phases are: A = Ca(CHO2)2; B = H3BO3.
