SDS Volume (2940)
Volume 66. Ammonium Phosphates, p None
Original Measurements
D'Ans, J.; Schreiner, O.; Z. Phys. Chem. 1911, 75U, 95-107.
Variables:
Room Temp: Composition at 25 °C
Prepared by:
Method/Apparatus/Procedure:
The isothermal method was used. $\ce{H3PO4}$ was precipitated as $\ce{NH4MgPO4.6H2O}$ and weighed as $\ce{Mg2P2O7}$. Ammonia was distilled into an acid solution and determined volumetrically.
Source and Purity of Materials:
- Commercial materials, pure.
Estimated Errors:
Ambient temperature: The temperature was controlled to within 0.05 k. No other details are given.
Mass concentration (m/v) (1): The compiler assumes the reproducibility of the analyses to be about ±0.5%.
Components:
- Ammonia, $\ce{ NH3 }$; [7664-41-7] NIST WebBook
- Phosphoric acid, $\ce{ H3PO4 }$; [7664-38-2] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility in the (NH4)3PO4-NH3-H3PO4-H2O system at 25°C.
| 100w1 | 100w2 | 100w3 | m1 (mol/kg) | m2 (mol/kg) | m3 (mol/kg) | m4 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|---|
| 12.6 | 0.82 | 86.5 | 7.42 | 0.084 | 8.57 | 0.097 | A |
| 8.55 | 2.0 | 89.5 | 5.02 | 0.20 | 5.61 | 0.22 | A |
| 5.04 | 4.5 | 90.5 | 2.95 | 0.46 | 3.26 | 0.51 | A |
| 5.18 | 10.0 | 84.8 | 3.04 | 1.02 | 3.58 | 1.20 | A |
| 5.65 | 12.9 | 81.4 | 3.32 | 1.32 | 4.08 | 1.62 | A |
| 8.14 | 22.7 | 69.1 | 4.78 | 2.32 | 6.92 | 3.36 | A |
| 11.0 | 31.1 | 58.0 | 6.48 | 3.16 | 11.2 | 5.45 | A + B |
| 10.9 | 31.7 | 57.4 | 6.42 | 3.23 | 11.2 | 5.63 | B |
| 11.0 | 36.7 | 52.3 | 6.46 | 3.74 | 12.3 | 7.15 | B |
| 11.2 | 39.3 | 49.5 | 6.56 | 4.01 | 13.2 | 8.10 | B |
| 11.5 | 42.5 | 45.9 | 7.78 | 4.34 | 14.8 | 9.45 | B |
| 12.4 | 47.3 | 40.3 | 7.26 | 4.83 | 18.0 | 12.0 | B |
| 12.2 | 47.2 | 40.6 | 7.16 | 4.82 | 17.6 | 11.9 | B |
| 12.2 | 47.3 | 40.5 | 7.14 | 4.83 | 17.6 | 11.9 | B + C |
| 12.2 | 47.3 | 40.4 | 7.18 | 4.83 | 17.8 | 11.9 | B + C |
| 12.2 | 47.3 | 40.5 | 7.14 | 4.83 | 17.6 | 11.9 | B + C |
| 12.2 | 47.3 | 40.5 | 7.14 | 4.83 | 17.6 | 11.9 | |
| 12.2 | 50.0 | 37.8 | 7.15 | 5.10 | 18.9 | 13.5 | |
| 11.7 | 55.9 | 32.5 | 6.86 | 5.70 | 21.1 | 17.6 | |
| 11.4 | 66.1 | 22.5 | 6.70 | 6.74 | 29.7 | 29.9 | C |
| 11.4 | 44.5 | 44.1 | 6.72 | 4.54 | 15.3 | 10.3 | C |
| 9.57 | 38.0 | 52.4 | 5.62 | 3.88 | 10.7 | 7.40 | C |
| 7.87 | 32.9 | 59.2 | 4.62 | 3.36 | 7.80 | 5.68 | C |
| 4.63 | 25.4 | 70.0 | 2.72 | 2.59 | 3.89 | 3.70 | C |
| 4.26 | 24.9 | 70.9 | 2.50 | 2.54 | 3.53 | 3.59 | C |
| 4.39 | 42.0 | 53.6 | 2.58 | 4.29 | 4.82 | 8.01 | C |
| 4.70 | 60.9 | 34.4 | 2.76 | 6.21 | 8.01 | 18.0 | C |
| 5.21 | 75.5 | 19.3 | 3.06 | 7.70 | 15.8 | 39.8 | C |
| 5.28 | 77.0 | 17.7 | 3.10 | 7.86 | 17.5 | 44.4 | C |
(a) These compositions are expressed as mol/kg of solution.
(b) These values were calculated by the compiler.
(c) The solid phases are: A = (NH4)3PO4; B = (NH4)2HPO4; C = NH4H2PO4.
(d) These solid phases were analyzed.
(e) Metastable solutions.
