SDS Volume (4674)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Kalacheva, V. G.; Eremeeva, I. L.; Schwartz, E. M.; Izv. Acad. Nauk. Latv. SSR, Ser. Khim. N 4, 406-9 (1977).
Variables:
Room Temp: Composition at 50 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
The isothermal method was used. The mixtures were shaken in sealed glass vessels for 5-6 hrs. The boric acid concentration was determined by titration with alkali using mannitol. The $\ce{Mg^{2+}}$ content was determined complexometrically using Complexon III. The composition of the solid phases was determined by the Schreinemakers method.
Source and Purity of Materials:
- PA grade boric acid was recrystallized from water. Magnesium formate dihydrate was obtained by the reaction of $\ce{Mg(OH)2}$ and formic acid. The solid was recrystallized twice from water.
Estimated Errors:
Ambient temperature: The temperature was controlled to within ±0.02°C.
Components:
- Magnesium formate, $\ce{ Mg(CHO2)2 }$; [557-39-1] 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 Mg(CHO2)2-H3BO3-H2O system at 50°C.
| 100w1 | 100w2 | m1 (mol/kg) | m2 (mol/kg) | Phase (s) () |
|---|---|---|---|---|
| 10.35 | - | 1.867 | - | A |
| 3.74 | 10.05 | 0.379 | 1.885 | A |
| 5.02 | 10.05 | 0.517 | 1.914 | A |
| 5.57 | 10.04 | 0.577 | 1.924 | A |
| 9.50 | 9.95 | 1.03 | 2.00 | A |
| 12.20 | 9.83 | 1.368 | 2.04 | A |
| 12.32 | 9.84 | 1.384 | 2.04 | A |
| 12.40 | 9.88 | 1.395 | 2.06 | A |
| 12.80 | 9.88 | 1.448 | 2.07 | A |
| 13.02 | 10.06 | 1.480 | 2.115 | A + B |
| 13.68 | 4.65 | 1.465 | 0.921 | B |
| 13.70 | 2.33 | 1.427 | 0.449 | B |
| - | 13.72 | - | 1.391 | B |
(a) The molality values were calculated by the compilers.
(b) The solid phases are: A = H3BO3; B = Mg(CHO2)2·2H2O.
