SDS Volume (3018)
Volume 66. Ammonium Phosphates, p None
Original Measurements
Zakirov, B. S.; Tukhtaev, S.; Beglov, B. M.; Uzb. Khim. Zh. 1974, 19.
Variables:
Composition and temperature.
Prepared by:
Method/Apparatus/Procedure:
A visual polythermic method was used.
Source and Purity of Materials:
- "Chemically pure" $\ce{NH4H2PO4}$ was used. The thiourea was recrystallized twice.
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
- Thiourea, $\ce{ CH4N2S }$; [62-56-6] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Remarks: Additional Data: Solubility isotherms in the 0°C to 50°C temperature range are given, but only in graphical form.
Points of simultaneous crystallization of two or three solid phases in the NH4H2PO4-CS(NH2)2-H2O system.
| $T$ (°C) | 100w1 | 100w2 | 100w3 | m1 (mol/kg) | m2 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|
| -0.6 | 0 | 5.2 | 94.8 | 0 | 0.72 | A + B |
| -2.0 | 4.8 | 4.1 | 91.1 | 0.46 | 0.59 | A + B |
| -3.1 | 9.6 | 3.5 | 86.9 | 0.96 | 0.53 | A + B |
| -4.2 | 14.5 | 3.2 | 82.3 | 1.53 | 0.51 | A + B |
| -4.5 | 15.8 | 3.2 | 81.0 | 1.70 | 0.52 | A + B + C |
| -4.2 | 18.0 | 0 | 82.0 | 1.91 | 0 | A + D |
| 1.0 | 17.2 | 4.2 | 78.6 | 1.90 | 0.70 | B + D |
| 7.5 | 18.9 | 5.3 | 75.8 | 2.17 | 0.92 | B + D |
| 22.5 | 22.7 | 7.8 | 69.5 | 2.84 | 1.5 | B + D |
| 28.0 | 24.5 | 9.0 | 66.5 | 3.20 | 1.8 | B + D + E |
| 33.0 | 32.4 | 0 | 67.6 | 4.17 | 0 | D + E |
| 36.8 | 27.0 | 11.0 | 62.0 | 3.79 | 2.33 | B + E |
| 50.6 | 30.8 | 13.8 | 55.4 | 4.83 | 3.27 | B + E |
(a) These values were calculated by the compiler.
(b) The solid phases are: A = ice; B = CS(NH2)2; C-NH4H2PO4; D = α-NH4H2PO4; E = β-NH4H2PO4.
