SDS Volume (2867)
Volume 66. Ammonium Phosphates, p None
Original Measurements
Shilling, N. K.; Stetsova, G. S.; Teknologiya Minerl'nykh Udobreniy 68-71 (1977).
Variables:
Composition and temperature
Prepared by:
Method/Apparatus/Procedure:
A polythermic method was used but no details are given. The nature of the solid phase was determined graphoanalytically (no details are given) and checked by IR spectroscopy.
Source and Purity of Materials:
- Chemically pure $\ce{NH4H2PO4}$ and $\ce{NH4F}$ were used.
Estimated Errors:
Ambient temperature: No information is given.
Mass concentration (m/v) (1): No information is given.
Components:
- Ammonium dihydrogenphosphate, $\ce{ NH4H2PO4 }$; [7722-76-1] NIST WebBook
- Ammonium fluoride, $\ce{ NH4F }$; [12125-01-8] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility isotherms in the NH4H2PO4-NH4F-H2O system.
| $T$ (°C) | 100w1 | 100w2 | 100w3 | m1 (mol/kg) | m2 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|
| -5 | 13.2 | 5 | 81.8 | 1.40 | 15 | A |
| -5 | 14.7 | 3 | 82.3 | 1.55 | 9 | A |
| -5 | 17.5 | 18.5 | 64 | 2.38 | 72.3 | A |
| -5 | 21 | 21 | 58 | 3.2 | 90 | A |
| -5 | 14 | 38 | 48 | 2.5 | 200 | B |
| -5 | 20.8 | 3E+1 | 49.2 | 3.68 | 150 | B + C |
| 0 | 15.4 | 5 | 79.6 | 1.68 | 1.7 | A |
| 0 | 17.3 | 3 | 79.7 | 1.89 | 1 | A |
| 0 | 19.0 | 14 | 67 | 2.47 | 5.6 | A |
| 0 | 22 | 21 | 57 | 3.4 | 9.9 | A |
| 0 | 22.5 | 29 | 48.5 | 4.03 | 16 | A |
| 0 | 14 | 38.5 | 47.5 | 2.56 | 21.9 | B |
| 5 | 18.5 | 3 | 78.5 | 2.05 | 1 | A |
| 5 | 18.2 | 5 | 76.8 | 2.06 | 2 | A |
| 5 | 2E+1 | 11 | 69 | 2.5 | 4.3 | A |
| 5 | 24 | 2E+1 | 56 | 3.7 | 9.6 | A |
| 5 | 24 | 28 | 48 | 4.3 | 16 | A |
| 5 | 22.5 | 29 | 48.5 | 4.03 | 16 | A + B |
| 5 | 18.5 | 39 | 42.5 | 3.78 | 25 | B |
| 10 | 21.5 | 4 | 74.5 | 2.51 | 1 | A |
| 10 | 22 | 6 | 72 | 2.7 | 2 | A |
| 10 | 26 | 28 | 46 | 4.9 | 16 | A |
| 10 | 27 | 2E+1 | 53 | 4.4 | 10 | A |
| 10 | 13 | 41 | 46 | 2.5 | 24 | B |
| 10 | 23 | 33 | 44 | 4.5 | 20 | B |
| 20 | 27 | 5 | 68 | 3.5 | 2 | A |
| 20 | 27 | 8 | 65 | 3.6 | 3 | A |
| 20 | 27 | 35 | 38 | 6.2 | 25 | A |
| 20 | 29 | 3E+1 | 41 | 6.1 | 20 | A |
| 20 | 3E+1 | 19 | 51 | 5.1 | 10 | A |
| 20 | 3E+1 | 26 | 44 | 5.9 | 16 | A |
| 20 | 26 | 37 | 37 | 6.1 | 27 | A + B |
| 30 | 3E+1 | 26 | 44 | 5.9 | 16 | A |
| 30 | 32 | 29 | 39 | 7.1 | 20 | A |
| 30 | 25 | 39 | 36 | 6.0 | 29 | B |
(a) The molalities were calculated by the compilers based on 100wi of the salts.
(b) The solid phases are: A = NH4H2PO4; B = NH4F; C = NH4F·H2O.
(c) There are obvious misprints in these data (100wi = 47 and 45, respectively) in the original article.
