Components:
(1) Cesium formate,
CsCHO2; [3495-36-1]
NIST WebBook
(2) Water,
H2O; [7732-18-5]
NIST WebBook
Original Measurements
Sidgwick, N. V.; Gentle, J. A. H. R.; J. Chem. Soc. 121, 1837 (1922).
Variables:
Ambient temperature: -0.77 - 265 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
The freezing points were measured in a Beckmann apparatus. Analysis was done gravimetrically by evaporating the solution to dryness. At higher temperatures mixtures were sealed in tubes and the temperature at which the last crystal disappeared on warming was observed.
Source and Purity of Materials:
- The cesium formate was prepared by neutralizing the carbonate with formic acid. Commercial 80% formic acid was distilled in a vacuum at 70°C with enough sulfuric acid to remove the water.
Estimated Errors:
Ambient temperature: No information is given.
Mass concentration (m/v) (1): No information is given.
Experimental Values:
Note: Melting point of cesium formate determined to be 265°C. Phase composition at 458C is B + C.Composition of equilibrium liquid phase.
| T (°C) | 100w1 | 100x1 | m1 (mol/kg)c | Phase (s)a |
|---|---|---|---|---|
| -7.7 x 10-1 | 4.0 | 4.2 x 10-1 | 2.3 x 10-1 | A |
| -1.72 | 8.11 | 8.86 x 10-1 | 4.96 x 10-1 | A |
| -3.44 | 14.29 | 1.662 | 9.37 x 10-1 | A |
| -5.27 | 19.62 | 2.414 | 1.372 | A |
| -8.12 | 26.75 | 3.476 | 2.052 | A |
| 1.0 | 77.07 | 25.37 | 18.89 | B |
| 21.0 | 81.69 | 31.09 | 25.07 | B |
| 26.2 | 83.25 | 33.44 | 27.93 | B |
| 32.2 | 84.81 | 36.09 | 31.38 | B |
| 39.2 | 86.88 | 40.11 | 37.22 | B |
| 42.7 | 88.67 | 44.18 | 43.98 | B |
| 44.6 | 90.42 | 48.83 | 53.05 | B |
| 45.0 | 90.81 | 50.0 | - | (m.p.) |
| 43.8 | 92.54 | 55.61 | 69.73 | (m.p.) |
| 42.6 | 93.47 | 59.14 | 80.46 | (m.p.) |
| 95.4 | 95.27 | 67.07 | 113.2 | C |
| 161.6 | 96.67 | 75.49 | 163.2 | C |
(a) The solid phases are: A = ice; B = CsCHO2·H2O; C = CsCHO2. (b) Melting point. (c) The molality values were calculated by the compilers.
