Compilation - Ammonium dihydrogenphosphate with Potassium dihydrogenphosphate and Water (IUPAC SDS Volume 66)
SDS Volume (2877)
Volume 66. Ammonium Phosphates, p None
Original Measurements
Bergman, A. G.; Gladkovskaya, A. A.; Galushkina, R. A.; Zh. Neorg. Khim. 1972, 17, 2055.
Variables:
Composition and temperature
Prepared by:
Method/Apparatus/Procedure:
The only information given is that a visually polythermic method [1] was used.
Source and Purity of Materials:
- Chemically pure salts were recrystallized and dried before use. Bidistilled water was used
Estimated Errors:
Ambient temperature: No information is given.
Mass concentration (m/v) (1): No information is given.
References
1 Bergman, A. G.; Luzhnaya, N. P.; Fiziko-Khimicheskie Osnovy Izucheniya i Ispol'zovaniya Solyanykh Mestorozhdeniy Khlorid-Sul'fatnogo Tipa, Moscow, IAN USSR (1951).
Components:
- Ammonium dihydrogenphosphate, $\ce{ NH4H2PO4 }$; [7722-76-1] NIST WebBook
- Potassium dihydrogenphosphate, $\ce{ KH2PO4 }$; [7778-77-0] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Remarks: Compiler's comment: It is not possible to construct a legitimate phase diagram on the basis of the data that are given. The concentration of component added has the meaning given only if the added component is a salt. When water is the added component, the relation 100wwater = 100 - 100wadd is valid. With this assumption the following compositions of points lying on the transition curve were calculated (next page).
Table 1. Authors Data
| $T$ (°C) | 100w2 | Phase (s) () |
|---|---|---|
| 6.0 | 11.5 | A + B |
| 14.2 | 11.6 | A + B |
| 17.6 | 17.3 | A + B |
| -4.5 | 20.5 | B + C |
| 25.0 | 32.6 | A + B |
| -4.0 | 18.2 | A + C |
| 13.6 | 24.5 | A + B |
| 14.0 | 25.0 | A + B |
| -3.6 | 14.3 | A + C |
| -4.0 | 10.3 | A + C |
(a) This is the mass % of component added.
(b) The solid phases are: A = β solid solution; B = α-NH4H2PO4; C = ice.
(a) The solid phases are: A = β-solid solution; B = α-NH4H2PO4; C = ice.
