IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Glass Ball as Bullet Solubility System: Sodium formate with Sodium chloride
Components:
   (1) Sodium chloride; NaCl; [7647-14-5]  NIST Chemistry WebBook for detail
   (2) Sodium formate; NaCHO2; [141-53-7]  NIST Chemistry WebBook for detail
Original Measurements:
   Leonesi, D.; Braghetti, M.; Cingolani, A.; Franzosini, P., Z. Naturforsch. 25a, 52-5 (1970).

 Variables:


Prepared By:
   P. Baldini

 Experimental Remarks:
   Note 1: In the original paper the results were shown in graphical form. The numerical values listed above were given in a personal communication from one of the authors (F.P.) to the compiler.
Note 2: The system could not be investigated above 300 ºC due to thermal instability of the formate.
Note 3: There is a eutectic at 249.8 ºC and 100x2 = 5.15.
Note 4: Previous investigations by the same group2 stated that the cryometric constant of sodium formate was K = 9.4 ± 0.2 K molality-1, and that
lim (ΔT/m) = 9.6 K molality-1
m→0                                           

(where ΔT is the experimental freezing point depression, and m is the molality of the solute) when NaCl was the solute. Consequently, the solubility of component (2) in component (1) in the solid state ought to be insignificant.

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)   

t/°CT/KMole Fraction2
257.5530.70
256.0529.20.95
254.5527.72.10
253.2526.43.00
251.6524.83.94
250.7523.94.60
249.8523.05.14
252.5525.75.22
259.5532.75.63
260.5533.75.70
266.8540.05.98
275.4548.66.48
286.3559.57.13
293.6566.87.55
298.9572.17.83
 Notes:
   a  The T/K values were calculated the compiler.

 Method/Apparatus/Procedure:
   A Pyrex device, suitable for work under an inert atmosphere, and allowing one to observe the system visually, was used (for details, refer to Ref.1. The initial crystallization temperatures were measured with a Chromel-Alumel thermouple checked by comparison with a certified Pt resistance thermometer, and connected to a L&N Type K-3 potentiometer.

 Source and Purity of Materials:
   C. Erba RP materials, dried by heating under vacuum, were used.

 Estimated Errors:
   Solubility: No information is given.
   Temperature: The compiler estimates the accuracy of the temperature measurements to be probably ± 0.1 K.

 References:
   1M. Braghetti; D. Leonesi; P. Franzosini, Ric. Sci. 38, 116 (1968).
   2D. Leonesi, G. Piantoni, G.Berchiesi, and P. Franzosini, Ric. Sci. 38, 702 (1968).