SDS Volume (4687)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Groschuff, E.; Ber. Dtsch. Chem. Ges. 36, 4351 (1903).
Variables:
Temperature: 266.7 - 312.2 $\pu{K}$
Prepared by:
Method/Apparatus/Procedure:
The freezing point method was used to study the system.
Source and Purity of Materials:
- $\ce{NH4CHO2.CH2O2}$ was prepared by the reaction of equimolar quantities of $\ce{NH4CHO2}$ and anhydrous formic acid. On cooling with ice to 283 K, small hexahedral plates separated out. No other information is given.
Estimated Errors:
Ambient temperature: Nothing is specified. The compiler estimates that the temperature was controlled to within ±0.5 K.
Components:
- Ammonium formate, $\ce{ NH4CHO2 }$; [540-69-2] NIST WebBook
- Formic acid, $\ce{ CH2O2 }$; [64-18-6] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Table 1. Solubility in the NH4CHO2-CH2O2-H2O system.
| $T$ (°C) | 100w1 | 100w2 | 100w3 | $100 x_{1}$ | $100 x_{2}$ | $100 x_{3}$ | Phase (s) () |
|---|---|---|---|---|---|---|---|
| -6.5 | 46.7 | 34.1 | 19.2 | 29.1 | 29.1 | 41.8 | A |
| 1.5 | 49.6 | 36.2 | 14.2 | 33.3 | 33.3 | 33.4 | A |
| 4 | 50.4 | 36.8 | 12.8 | 34.6 | 34.6 | 30.8 | A |
| 6 | 51.3 | 37.4 | 11.3 | 36.1 | 36.1 | 27.8 | A |
| 8.5 | 52.1 | 38.0 | 9.9 | 37.5 | 37.5 | 25 | A |
| -7 | 49.6 | 36.2 | 14.2 | 33.3 | 33.3 | 33.4 | B |
| 13 | 53.0 | 38.6 | 8.4 | 39.2 | 39.1 | 22 | C |
| 29 | 55.8 | 40.7 | 3.5 | 45.1 | 45.0 | 9.9 | C |
| 39 | 57.8 | 42.2 | 0 | 50.0 | 50.0 | 0 | C |
(a) These values were calculated by the compiler.
(b) The solid phases are: A = NH4CHO2·CH2O2; B = NH4CHO2 (labile); C = NH4CHO2 (stable).
(a) The solid phases are: A = NH4CHO2 (stable); B = NH4CHO2 (unstable); C = NH4CHO2·HCHO2 (unstable); D = NH4CHO2·HCHO2 (stable).
