IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Sodium formate with Sodium hydroxide and Water

Components:
   (1) Sodium formate; NaCHO2; [141-53-7]  NIST Chemistry WebBook for detail
   (2) Sodium hydroxide; NaOH; [1310-73-2]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Centola, G.P.; Rosso, E.R.; Mazzoccia, V.C., J. Chem. Eng. Data 25, 170-1 (1980).

Variables:

   Concentration = Composition at 60 ºC

Prepared By:
   Chr. Balarew and St. Trendafilova

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

Liquid phase composition of the NaCHO₂-NaOH-H₂O system at 60 °C.
Chemical₁	Phase	Mass Fraction w₁	m₁ [mol kg-1]^a	Chemical₂	Mass Fraction w₂	m₂ [mol kg-1]^a
NaOH	Liquid	0.0	0.0	NaCHO2	54.7	17.8
NaOH	Liquid	3.3	1.8	NaCHO2	50.0	15.7
NaOH	Liquid	7.3	3.8	NaCHO2	44.2	13.4
NaOH	Liquid	11.8	5.78	NaCHO2	37.2	10.7
NaOH	Liquid	16.2	7.66	NaCHO2	30.9	8.59
NaOH	Liquid	21.4	10.0	NaCHO2	25.1	6.90
NaOH	Liquid	32.8	14.6	NaCHO2	11.1	2.91
NaOH	Liquid	40.6	18.7	NaCHO2	5.1	1.4
NaOH	Liquid	63.6	27.2	NaCHO2	0.0	0.0

Notes:
   ^a  These values were calculated by the compilers.

Method/Apparatus/Procedure:
   Weighed amounts of NaOH and formic acid were dissolved in deionized 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:

   Temperature: Accuracy of temperature measurement was ± 0.05°C.