SDS Volume
Volume 66. Ammonium Phosphates, p None
Source Publication
Babenko, A. M.; Vorob'eva, T. A.; Zh. Prikl. Khim. 49, 1502-6 (1976).
Conditions:
NaH2PO4 in a mixture containing a mole ratio of NH4H2PO4/(NH4)2HPO4 = 1.
Compiler:
Methodology:
An improved polythermic method [1] was used.
Sample Information:
- Reagent grade salts were recrystallized and dried. The ammonium salts were dried at 40°C to 50°C. The sodium salt was dried at 105°C. The material designated "mixture" was prepared by mixing equimolar amounts of $\ce{NH4H2PO4}$ and $\ce{(NH4)2HPO4}$ and homogenizing them by grinding in a mortar.
Measurement Errors:
Ambient temperature: No information is given.
Mass concentration (m/v) (1): No information is given.
Methodology Citation
1 Erayzer, L. N.; Kaganskiy, I. M.; Zavod. Lab. 1967, 1, 119.
System Components:
- Ammonium dihydrogenphosphate, $\ce{ NH4H2PO4 }$; [7722-76-1] NIST WebBook
- Diammonium hydrogenphosphate, $\ce{ (NH4)2HPO4 }$; [7783-28-0] NIST WebBook
- Sodium dihydrogenphosphate, $\ce{ NaH2PO4 }$; [7558-80-7] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
| $T$ (°C) | 100w1 | 100w2 | 100w3 | 100w4 | m1 (mol/kg) | m4 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|---|
| -8.6 | 38.6 | 17.97 | 20.63 | 0.00 | 2.54 | 0.00 | A + C |
| -8.4 | 32.0 | 14.90 | 17.10 | 6.8 | 2.11 | 0.92 | A + C |
| -8.4 | 20.4 | 9.50 | 10.90 | 15.92 | 1.29 | 2.08 | A + C |
| -9.4 | 9.8 | 4.56 | 5.24 | 27.06 | 0.63 | 3.57 | A + C |
| -8.0 | 21.25 | 9.89 | 11.36 | 15.0 | 1.35 | 1.96 | A + C |
| -9.0 | 16.0 | 7.45 | 8.55 | 20.0 | 1.01 | 2.60 | A + C |
| -11.0 | 6.8 | 3.16 | 3.63 | 32.0 | 0.45 | 4.36 | A + C |
| 0.5 | 6.0 | 2.79 | 3.21 | 37.6 | 0.43 | 5.55 | A + B + C |
| -8.8 | 0.0 | 0.0 | 0.0 | 33.5 | 0.0 | 4.20 | A + B |
| -12.0 | 2.4 | 1.12 | 1.28 | 40.0 | 0.17 | 5.79 | A + B |
| 19.2 | 8.0 | 3.72 | 4.28 | 41.4 | 0.64 | 6.82 | B + C |
| 25.2 | 8.0 | 3.72 | 4.28 | 46.0 | 0.70 | 8.33 | B + C |
| 35.0 | 9.8 | 4.56 | 5.24 | 48.708 | 0.96 | 9.78 | B + C + D |
| 39.0 | 61.0 | 28.40 | 32.60 | 0.0 | 6.33 | 0.0 | C + D |
| 45.6 | 56.0 | 26.07 | 29.93 | 4.4 | 5.72 | 0.92 | C + D |
| 48.3 | 48.0 | 22.34 | 25.65 | 10.4 | 4.67 | 2.08 | C + D |
| 44.6 | 36.0 | 16.76 | 19.24 | 19.2 | 3.25 | 3.57 | C + D |
| 50.3 | 28.0 | 13.04 | 14.96 | 28.8 | 2.62 | 5.55 | C + D |
| 56.0 | 24.0 | 11.17 | 12.83 | 33.2 | 2.27 | 6.46 | C + D |
| 55.0 | 20.0 | 9.31 | 10.69 | 40.0 | 2.02 | 8.33 | C + D |
| 67.0 | 20.0 | 9.31 | 10.69 | 43.2 | 2.20 | 9.78 | C + D |
| 40.2 | 0.0 | 0.0 | 0.0 | 56.0 | 0.0 | 10.60 | B + E |
| 43.5 | 1.8 | 0.84 | 0.96 | 55.0 | 0.17 | 10.61 | B + E |
| 46.0 | 4.75 | 2.21 | 2.54 | 52.5 | 0.45 | 10.23 | B + E |
| 42.0 | 8.0 | 3.72 | 4.28 | 52.44 | 0.82 | 11.04 | D + E |
| 50.5 | 8.0 | 3.72 | 4.28 | 55.2 | 0.88 | 12.50 | D + E |
| 49 | 8.9 | 4.14 | 4.76 | 55.5 | 1.01 | 12.99 | D + E + F |
| 57.2 | 0.0 | 0.0 | 0.0 | 60.8 | 0.0 | 12.92 | E + F |
| 59.8 | 1.6 | 0.74 | 0.86 | 60.0 | 0.17 | 13.02 | E + F |
| 63.5 | 4.2 | 1.96 | 2.24 | 58.0 | 0.45 | 12.78 | E + F |
| 68.4 | 11.25 | 5.24 | 6.01 | 55.0 | 1.35 | 13.58 | E + F |
(a) "Mixture" is an equimolar mixture of NH4H2PO4 and (NH4)2HPO4.
(b) These values were calculated by the compiler.
(c) The molalities were calculated by the compiler. The units are: mol kg-1.
(d) The solid phases are: A = ice; B = NaH2PO4·2H2O; C = NH4H2PO4; D = (NH4)2HPO4; E = NaH2PO4·H2O; F = NaH2PO4.
