SDS Volume (4677)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Kuanisheva, N. A.; Khazikhanova, B. H.; Kalacheva, V. G.; Zh. Neorg. Khim. 31, 2426-8 (1986).
Variables:
Room Temp: Composition at 25 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
The isothermal method was used. Equilibrium was attained in 5-6 hours. The glass vessels in the thermostat were coated with glycerin.
Source and Purity of Materials:
- 75% p.a. grade $\ce{H3PO4}$ was used. p.a. grade calcium formate was recrystallized.
Estimated Errors:
Ambient temperature: t = ±0.1°C.
Components:
- Calcium formate, $\ce{ Ca(CHO2)2 }$; [544-17-2] NIST WebBook
- Phosphoric acid, $\ce{ H3PO4 }$; [7664-38-2] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility values in the Ca(CHO2)2-H3PO4-H2O system at 25°C.
| 100w1' | 100w2' | 100w1 | 100w2 | m1 (mol/kg) | m2 (mol/kg) | m3 (mol/kg) | m4 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|---|---|
| 7.41 | 0 | 17.19 | - | 1.427 | 0 | 1.595 | - | A |
| 5.26 | 0.51 | 12.20 | 0.697 | 0.995 | 0.038 | 1.076 | 0.082 | B |
| 5.06 | 0.66 | 11.73 | 0.906 | 0.957 | 0.049 | 1.032 | 0.106 | B |
| 4.25 | 1.15 | 9.86 | 1.593 | 0.801 | 0.086 | 0.856 | 0.184 | B |
| 4.2 | 1.4 | 9.74 | 1.933 | 0.793 | 0.104 | 0.847 | 0.223 | C |
| 4.47 | 5.24 | 10.37 | 7.235 | 0.883 | 0.409 | 0.967 | 0.896 | C |
| 6.0 | 12.00 | 13.92 | 16.569 | 1.305 | 1.031 | 1.539 | 2.433 | D |
| 4.11 | 20.58 | 9.53 | 28.417 | 0.973 | 1.925 | 1.180 | 4.674 | E |
| 2.33 | 30.83 | 5.40 | 42.570 | 0.622 | 3.249 | 0.798 | 8.350 | E |
| 2.8 | 23.68 | 6.49 | 32.69 | 0.679 | 2.269 | 0.820 | 5.485 | E |
(a) The solid phases are: A = Ca(CHO2)2; B = Ca(CHO2)2 + CaHPO4; C = CaHPO4; D = Ca(H2PO4)2·H2O + CaHPO4; E = Ca(H2PO4)2.
(b) The molality values were calculated by the compilers.
