SDS Volume (2904)
Volume 66. Ammonium Phosphates, p None
Original Measurements
Nabiev, M. N.; Tukhtaev, S.; Narkhodzaev, A. Kh.; Yunusov, D. Kh.; Zh. Neorg. Khim. 21, 3152 (1976).
Variables:
Temperature and composition.
Prepared by:
Method/Apparatus/Procedure:
Presumably some sort of visual polythermic method was used (compiler), but no details are given.
Source and Purity of Materials:
- Diammonium hydrogenphosphate was recrystallized before use. Urea nitrate was synthesized from urea and reagent grade nitric acid.
Estimated Errors:
Ambient temperature: No details are given.
Mass concentration (m/v) (1): No details are given.
Components:
- Diammonium hydrogenphosphate, $\ce{ (NH4)2HPO4 }$; [7783-28-0] NIST WebBook
- Urea nitrate, $\ce{ CO(NH2)2.HNO3 }$; [124-47-0] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Nonvariant and monovariant points in the (NH4)2HPO4-CO(NH2)2.HNO3-H2O system.
| $T$ (°C) | 100w1 | w2 | 100w3 | m1 (mol/kg) | m2 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|
| -2.8 | 8.0 | 0.0 | 92.0 | 0.7 | 0.0 | Ice + A |
| -3.6 | 9.8 | 2.0 | 88.2 | 0.9 | 0.2 | Ice + A |
| -8.0 | 15.8 | 8.4 | 75.8 | 1.7 | 0.8 | Ice + A |
| -12.4 | 17.8 | 11.0 | 71.2 | 2.0 | 1.2 | Ice + A + B |
| -8.5 | 23.0 | 15.4 | 61.6 | 3.0 | 1.9 | A + B |
| -5.5 | 32.0 | 20.0 | 48.0 | 5.4 | 3.2 | A + B |
| -7.0 | 32.6 | 20.2 | 47.2 | 5.6 | 3.2 | A + B |
| 30.0 | 40.0 | 24.0 | 36.0 | 9.0 | 5.0 | A + B |
| -9.0 | 12.4 | 17.4 | 70.2 | 1.4 | 1.9 | Ice + B + C |
| -7.2 | 8.0 | 20.0 | 72.0 | 0.9 | 2.1 | Ice + C |
| -5.5 | 0.0 | 25.0 | 75.0 | 0.0 | 2.5 | Ice + C |
| -10.0 | 12.0 | 22.0 | 66.0 | 1.5 | 2.5 | B + C |
| -17.5 | 11.0 | 26.6 | 62.4 | 1.4 | 3.2 | B + C + D |
| -10.5 | 6.8 | 31.3 | 61.9 | 0.9 | 3.8 | C + D |
| 15.0 | 0.0 | 39.2 | 60.8 | 0.0 | 4.9 | C + D |
| -11.0 | 13.8 | 31.0 | 55.2 | 2.0 | 4.3 | B + D |
| -2.0 | 15.6 | 33.6 | 50.8 | 2.5 | 5.0 | B + D |
| 28.0 | 19.6 | 40.2 | 40.2 | 4.0 | 7.6 | B + D |
| 49.0 | 22.2 | 44.4 | 33.4 | 5.4 | 10.1 | B + D |
(a) The molalities were calculated by the compiler.
(b) The solid phases are: A = (CO(NH2)2·HNO3; B = NH4H2PO4; C = (NH4)2HPO4·2H2O; D = NH4NO3; E = (NH4)2HPO4.
