SDS Volume (4826)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Portnova, S. M.; Palitskaya, T. A.; Zh. Neorg. Khim. 39, 163-168 (1994).
Variables:
Room Temp: Composition at 25 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
The isothermal solubility method was used. Four weeks were allowed for attainment of the equilibrium at a constant temperature. The composition of the liquid and wet solid phases were determined as follows:The $\ce{K^{+}}$ content was determined gravimetrically by the tetraphenylborate method. $\ce{Mn^{2+}}$ was determined complexometrically in basic medium, in the presence of 10% solution of N$\ce{H2O}$H•HCl using Eriochrome Black T as indicator. The composition of the solid phases was determined by elemental analysis, thermogravimetrically, crystallooptically and by X-ray diffraction. The composition of the suction dried solid phase was determined by the Schreinemakers' method also.
Source and Purity of Materials:
- $\ce{KCHO2}$ was obtained from $\ce{KOH}$ and $\ce{H2CO2}$ PA grade [1]. $\ce{Mn(CHO2)2}$ was obtained from $\ce{Mn(CHO2)2.2H2O}$ 'pure' grade through recrystallization (double recrystallization).
References
1 Itkina, L. S.; Chaplygina, N. M.; Petrova, E. V.; Russ. J. Inorg. Chem. 24, 440-3 (1979).
Components:
- Potassium formate, $\ce{ KCHO2 }$; [590-29-4] NIST WebBook
- Manganese(II) formate, $\ce{ Mn(CHO2)2 }$; [3251-96-5] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility values in the KCHO2-Mn(CHO2)2-H2O system at 25°C.
| 100w2 | 100w1 | m2 (mol/kg) | m1 (mol/kg) | Phase (s) () |
|---|---|---|---|---|
| 6.94 | - | 0.89 | - | A |
| 2.89 | 12.29 | 0.41 | 1.00 | A |
| 2.66 | 18.16 | 0.40 | 1.58 | A |
| 2.76 | 21.26 | 0.43 | 1.93 | A |
| 3.14 | 25.80 | 0.53 | 2.50 | A |
| 3.45 | 28.22 | 0.60 | 2.85 | A + B |
| 3.32 | 28.30 | 0.58 | 2.86 | B |
| 1.98 | 33.78 | 0.37 | 3.63 | B |
| 1.43 | 38.46 | 0.28 | 4.41 | B |
| 1.05 | 44.36 | 0.23 | 5.61 | B |
| 0.88 | 48.96 | 0.21 | 6.73 | B |
| 0.84 | 52.88 | 0.22 | 7.88 | B |
| 0.81 | 55.02 | 0.22 | 8.59 | B |
| 0.78 | 57.50 | 0.22 | 9.51 | B |
| 0.77 | 61.16 | 0.24 | 11.08 | B |
| 0.77 | 67.08 | 0.28 | 14.40 | B |
| 0.79 | 70.20 | 0.32 | 16.70 | B + C |
| 0.02 | 77.95 | 0.01 | 24.41 | C |
| 0.02 | 80.29 | 0.01 | 28.13 | C |
| 0.02 | 80.50 | 0.01 | 28.51 | C |
| - | 81.82 | - | 31.05 | C |
(a) The solid phases are: A = Mn(CHO2)2, B = KMn(CHO2)3, C = KCHO2.
(b) The molality values were calculated by the compilers.
