Compilation - Ammonium dihydrogenphosphate with Diammonium dihydrogendiphosphate and Water (IUPAC SDS Volume 66)
SDS Volume (2935)
Volume 66. Ammonium Phosphates, p None
Original Measurements
Chulanova, G. A.; Mukhina, L. S.; Shipyatskaya, R. I.; Taran, A. I.; Zh. Prikl. Khim. 1976, 49, 1933.
Variables:
Room Temp: Composition at 50 and 70 °C
Prepared by:
Method/Apparatus/Procedure:
The visual polythermic method was used. All experimental details are described in [1].
Source and Purity of Materials:
- The only information given is that $\ce{(NH4)2H2P2O7}$ was prepared by heating $\ce{(NH4)4P2O7}$ to 125°C.
Estimated Errors:
Mass concentration (m/v) (1): No information is given.
References
1 Chulanova, G. A.; Shipyatskaya, R. I.; Mukhina, L. S.; Zh. Prikl. Khim. 1974, 47, 1637.
Components:
- Ammonium dihydrogenphosphate, $\ce{ NH4H2PO4 }$; [7722-76-1] NIST WebBook
- Diammonium dihydrogendiphosphate, $\ce{ (NH4)2H2P2O7 }$; [13597-86-9] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Table 1. Solubility values for the (NH4)2H2P2O7-NH4H2PO4-H2O system.
| $T$ (°C) | w1 | 100w2 | 100w3 | m1 (mol/kg) | m2 (mol/kg) | m3 (mol/kg) | m4 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|---|---|
| 50 | 0.0 | 40.5 | 59.5 | 0.0 | 5.92 | 0.0 | 2.96 | A |
| 50 | 6.3 | 37.7 | 56.0 | 0.53 | 5.85 | 0.53 | 2.93 | A |
| 50 | 9.1 | 36.4 | 54.5 | 0.79 | 5.81 | 0.79 | 2.90 | A |
| 50 | 16.3 | 32.7 | 51.0 | 1.51 | 5.57 | 1.51 | 2.78 | A |
| 50 | 26.7 | 26.7 | 46.6 | 2.70 | 4.98 | 2.72 | 2.50 | A |
| 50 | 34.8 | 23.2 | 42.0 | 3.91 | 4.80 | 3.91 | 2.40 | A |
| 50 | 40.0 | 20.0 | 40.0 | 4.72 | 4.35 | 4.72 | 2.17 | A |
| 50 | 48.0 | 16.0 | 36.0 | 6.29 | 3.86 | 6.29 | 1.53 | B |
| 50 | 51.0 | 12.8 | 36.2 | 6.64 | 3.07 | 6.65 | 1.53 | B |
| 50 | 53.6 | 8.9 | 37.5 | 6.74 | 2.1 | 6.74 | 1.03 | B |
| 50 | 61.0 | 0.0 | 39.0 | 7.38 | 0.0 | 7.38 | 0.00 | B |
(a) These values were calculated by the compiler.
(b) The solid phases are: A = NH4H2PO4: B = (NH4)2H2P2O7.
(c) This is an obvious error. The compiler thinks this value should be 1.93.
(a) These values were calculated by the compiler.
(b) The solid phases are: A = NH4H2PO4: B = (NH4)2H2P2O7.
