Nomenclature
CAS number: 13601-19-9
Tetrasodium hexakis(cyano-
C)ferrate(4); sodium hexacyanoferrate(II); yellow prussiate of soda; sodium prussiate yellow.
C
6FeN
6Na
4; mol wt 303.91.
C 23.71%, Fe 18.38%, N 27.65%, Na 30.26%.
Na
4Fe(CN)
6.
Description and references
Review of properties, chemistry and syntheses:
The Chemistry of Ferrocyanides, American Cyanamid Co.
(Beacon Press, New York, 1953) 112 pp.
Derivative
Decahydrate.
Properties
Pale yellow, monoclinic, slightly efflorescent
crystals. Steady dehydration occurs >50°. Becomes anhydr at 81.5°.
Dec 435°, forming sodium cyanide, iron, carbon, and nitrogen. Soly
in water at 1°: 10.2% (calcd as the anhydr salt); at 17°: 14.7%;
at 25°: 17.6%; at 53°: 28.1%; at 85°: 39%; at 96.6°: 39.7%. Practically
insol in most organic solvents.Caution
Do not mix with hot or concd acids
and do not expose solns to sunlight for any length of time to avoid
generation of hydrogen cyanide. Waste ferrocyanides in streams and
lakes should not exceed 2 ppm because irradiated solns become toxic
to fish, G. E. Burdick, M. Lipscheutz, C.A. 44, 10939f (1950). Toxicity: Because of
strong chemical bondage between the cyanide groups and the iron, ferrocyanides
have a low order of toxicity.Use
Addition of sodium ferrocyanide solns to slightly
acidic solns of iron salts causes precipitation of insol Prussian
blue (ferric ferrocyanide), Fe
4[Fe(CN)
6]
3. Alkaline solns yield sol Prussian blue, NaFe[Fe(CN)
6]. Sodium ferrocyanide forms gels with heavy metals in general.
Used in ore flotation. In photography for bleaching, toning, and
fixing. To prevent caking of rock salt and foods. Additive to pickling
baths. Peptizing agent in rubber. Arc stabilizer in welding rod
coatings. Emulsion polymerization catalyst.