IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


Glass Ball as Bullet Solubility System: Sodium formate with Sodium tetraborate and Water

Components:
   (1) Sodium formate; NaCHO2; [141-53-7]  NIST Chemistry WebBook for detail
   (2) Sodium tetraborate; Na2B4O7; [1330-43-4]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Berniyazova, D.G.; Kalacheva, V.G.; Schwartz, E.M., Zh. Neorg. Khim. 31, 1045-8 (1986).

Variables:

   Concentration = Composition at 15 ºC

Prepared By:
   St. Tepavitcharova and St. Trendafilova

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
  
Solubility values in the NaCHO2-Na2B4O7-H2O system at 15 °C.
Chemical1PhaseMass Fraction w1m1 [mol kg-1]aChemical2Mass Fraction w2m2 [mol kg-1]aSolid Phase(s)b
Na2B4O7Liquid2.790.14NaCHO2--------A
Na2B4O7Liquid2.730.15NaCHO26.140.99A
Na2B4O7Liquid2.530.15NaCHO212.632.19A
Na2B4O7Liquid2.470.15NaCHO218.243.38A
Na2B4O7Liquid2.240.14NaCHO220.523.91A
Na2B4O7Liquid2.040.14NaCHO224.164.81A
Na2B4O7Liquid1.940.13NaCHO225.355.13A
Na2B4O7Liquid1.590.11NaCHO229.526.30A
Na2B4O7Liquid1.470.11NaCHO231.526.92A
Na2B4O7Liquid1.230.10NaCHO235.218.15A
Na2B4O7Liquid1.170.10NaCHO237.889.14A
Na2B4O7Liquid1.090.09NaCHO239.269.68A
Na2B4O7Liquid0.980.08NaCHO239.989.96A
Na2B4O7Liquid0.860.07NaCHO240.6410.22A+B
Na2B4O7Liquid0.630.05NaCHO240.5610.14B
Na2B4O7Liquid--------NaCHO241.8210.57B
Notes:
   a  These values were calculated by the compilers.
   b  The solid phases are: A = Na2B4O7•10H2O; B = NaCHO2.

Method/Apparatus/Procedure:
   The isothermal method was used. Equilibrium was achieved within 4 hours. The boron concentration was determined by titration with alkali using phenolphtalein and mannitol, after the sample had been evaporated to dryness, ignited at 60 °C and dissolved in boiling HCl.1 The formate content was determined from the carbon content by ignition. The composition of the solid phases was determined by the Schreinemakers' method.

Source and Purity of Materials:
   p.a. grade NaCHO2 and suprapure grade Na2B4O7 were used.

Estimated Errors:
   Solubility: Solid phase B is probably NaCHO2•2H2O.

References:
   1Yu. N. Knipovich and Yu. V. Morachevskii, Analysis of Mineral Ores, 3rd ed., (L.Gostechizdat, p. 281, 1959).