Components:
(1) Sodium formate,
NaCHO2; [141-53-7]
NIST WebBook
(2) Sodium hydroxide,
NaOH; [1310-73-2]
NIST WebBook
(3) Water,
H2O; [7732-18-5]
NIST WebBook
Original Measurements
Centola, P. G.; Rosso, R. E.; Mazzoccia, C. V.; J. Chem. Eng. Data 25, 170-1 (1980).
Variables:
Ambient temperature: Composition at 21 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
Weighed amounts of NaOH and formic acid were dissolved in de-ionized water and placed in closed 250 cm3 flasks. The flasks were placed in a constant temperature bath. Equilibrium was reached in 6 h. Samples were removed after 24 h and analyzed. The sodium formate content was determined by adding excess KMnO4 and titrating the excess iodometrically. NaOH was determined by titration with formic acid.
Source and Purity of Materials:
- Carlo Erba pure reagents were used.
Estimated Errors:
Ambient temperature: Accuracy of temperature measurement was ±0.05°C.
Experimental Values:
Liquid phase composition of the NaCHO2-NaOH-H2O system at 21°C.
| 100w2 | 100w1 | m2 (mol/kg)a | m1 (mol/kg)a |
|---|---|---|---|
| 0.0 | 50.3 | 0.0 | 14.9 |
| 1.7 | 47.3 | 8.4 x 10-1 | 14.0 |
| 3.7 | 45.4 | 1.82 | 13.1 |
| 8.8 | 36.9 | 4.05 | 9.99 |
| 9.9 | 35.5 | 4.53 | 9.56 |
| 12.0 | 31.6 | 5.32 | 8.24 |
| 16.0 | 26.3 | 6.93 | 6.7 |
| 18.6 | 22.2 | 7.85 | 5.51 |
| 21.5 | 19.2 | 9.06 | 4.76 |
| 24.1 | 16.6 | 10.1 | 3.93 |
| 32.4 | 8.2 | 13.6 | 2.0 |
| 35.5 | 5.6 | 15.1 | 1.4 |
| 52.1 | 0.0 | 27.2 | 0.0 |
(a) These values were calculated by the compilers.
