SDS Volume (4845)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Chaplygina, N. M.; Itkina, L. S.; Zh. Neorg. Khim. 28, 261-3 (1983).
Variables:
Room Temp: 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 potassium content of both phases was determined by flame photometry. The bismuth content was determined complexometrically. The composition of the solid phases was determined by Schreinemakers' method, by IR spectroscopy, TG analysis and X-ray diffraction.
Source and Purity of Materials:
- Bismuth formate was prepared by the reaction of p.a. grade $\ce{Bi2O3}$ with 40% formic acid [1]. $\ce{KCHO2}$ was prepared by the reaction of 85% p.a. grade formic acid with $\ce{KOH}$. The crystals were washed with ethanol and dried over sulfuric acid.
Estimated Errors:
Ambient temperature: No information is given.
Mass concentration (m/v) (1): No information is given.
References
Components:
- Potassium formate, $\ce{ KCHO2 }$; [590-29-4] NIST WebBook
- Bismuth triformate, $\ce{ Bi(CHO2)3 }$; [25573-24-4] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility values in the KCHO2-Bi(CHO2)3-H2O system at 25°C.
| 100w1 | 100w2 | m1 (mol/kg) | m2 (mol/kg) | Phase (s) () |
|---|---|---|---|---|
| 45.58 | 0.59 | 10.07 | 0.032 | A |
| 47.00 | 0.44 | 10.63 | 0.024 | A |
| 48.50 | 0.48 | 11.30 | 0.027 | A |
| 50.93 | 0.37 | 12.44 | 0.022 | A |
| 61.87 | 0.34 | 19.47 | 0.026 | A |
| 62.60 | 0.24 | 20.03 | 0.019 | A |
| 65.64 | 0.23 | 22.87 | 0.020 | A |
| 74.29 | 0.14 | 34.55 | 0.016 | A |
| 76.05 | 0.20 | 38.07 | 0.024 | A |
| 77.33 | 0.19 | 40.90 | 0.025 | A |
| 79.48 | 0.23 | 46.56 | 0.033 | A + B |
(a) The solid phases are: A = K2Bi(CHO2)5 and B = KCHO2.
(b) The molality values were calculated by the compilers.
