Sodium ferrocyanide

Sodium ferrocyanide^[1]
Names
	IUPAC name Tetrasodium [hexacyanoferrate(II)]
	Other names Yellow prussiate of soda (YPS), Tetrasodium hexacyanoferrate, Gelbnatron, Ferrocyannatrium, sodium hexacyanoferrate(II), Yellow blood salt[citation needed]
Identifiers
CAS Number	13601-19-9 ;
3D model (JSmol)	Interactive image;
ECHA InfoCard	100.033.696
EC Number	237-081-9;
E number	E535 (acidity regulators, ...)
PubChem CID	26129;
UNII	5HT6X21AID ;
CompTox Dashboard (EPA)	DTXSID3051337 ;
	show InChI
	show SMILES
Properties
Chemical formula	Na4[Fe(CN)6]
Molar mass	303.91 g/mol
Appearance	pale yellow crystals
Odor	odorless
Density	1.458 g/cm3
Melting point	435 °C (815 °F; 708 K) (anhydrous) ; 81.5 °C (178.7 °F; 354.6 K) (decahydrate) (decomposes)
Solubility in water	10.2 g/100 mL (10 °C) ; 17.6 g/100 mL (20 °C) ; 39.7 g/100 mL (96.6 °C)
Refractive index (nD)	1.530
Structure
Crystal structure	monoclinic
Hazards
S-phrases (outdated)	S22 S24 S25
Related compounds
Other anions	Sodium ferricyanide (Red prussiate of soda)
Other cations	Potassium ferrocyanide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
	(what is ?)
	Infobox references

Sodium ferrocyanide is the sodium salt of the coordination compound of formula [Fe(CN)₆]⁴⁻. In its hydrous form, Na₄Fe(CN)₆ • 10H₂O (sodium ferrocyanide decahydrate), it is sometimes known as yellow prussiate of soda. It is a yellow crystalline solid that is soluble in water and insoluble in alcohol. The yellow color is the color of ferrocyanide anion. Despite the presence of the cyanide ligands, sodium ferrocyanide has low toxicity (acceptable daily intake 0–0.025 mg/kg body weight^[2]). The ferrocyanides are less toxic than many salts of cyanide, because they tend not to release free cyanide.^[3] However, like all ferrocyanide salt solutions, addition of an acid can result in the production of hydrogen cyanide gas, which is toxic.

Uses[]

When combined with iron, it converts to a deep blue pigment called Prussian blue, Fe^III
₄[Fe^II
(CN)
₆]
₃.^[4] It is used as a stabilizer for the coating on welding rods. In the petroleum industry, it is used for removal of mercaptans.

In the EU, ferrocyanides (E 535–538) were, as of 2018, solely authorized as additives in salt and salt substitutes, where they serve as an anticaking agents. Kidneys are the organ for ferrocyanide toxicity, but ferrocyanides are of no safety concern at the levels at which they are used.^[5]

Production[]

Sodium ferrocyanide is produced industrially from hydrogen cyanide, ferrous chloride, and calcium hydroxide, the combination of which affords Ca₂[Fe(CN)₆] • 11H₂O. A solution of this salt is then treated with sodium salts to precipitate the mixed calcium-sodium salt CaNa₂[Fe(CN)₆], which in turn is treated with sodium carbonate to give the tetrasodium salt.^[6]

References[]

^ Sodium ferrocyanide MSDS Archived 2010-05-17 at the Wayback Machine
^ "Toxicological evaluation of some food additives including anticaking agents, antimicrobials, antioxidants, emulsifiers and thickening agents". World Health Organization, Geneva. 1974. Retrieved 18 May 2009.
^ Holleman, A. F.; Wiberg, E. (2001). Inorganic Chemistry. San Diego: Academic Press. ISBN 0-12-352651-5.
^ "Prussian blue". Encyclopædia Britannica. Retrieved 18 May 2009.
^ Peter Aggett, Fernando Aguilar, Riccardo Crebelli, Birgit Dusemund, Metka Filipič, Maria Jose Frutos, Pierre Galtier, David Gott, Ursula Gundert‐Remy, Gunter Georg Kuhnle, Claude Lambré, Jean‐Charles Leblanc, Inger Therese Lillegaard, Peter Moldeus, Alicja Mortensen, Agneta Oskarsson, Ivan Stankovic, Ine Waalkens‐Berendsen, Rudolf Antonius Woutersen, Matthew Wright and Maged Younes. (2018). "Re‐evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide (E 536) and calcium ferrocyanide (E 538) as food additives". EFSA Journal. 16 (7): 5374. doi:10.2903/j.efsa.2018.5374.CS1 maint: multiple names: authors list (link)
^ Gail, E.; Gos, S.; Kulzer, R.; Lorösch, J.; Rubo, A.; Sauer, M.; Kellens, R.; Reddy, J.; Steier, N. (2011). "Cyano Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_159.pub3.

[1] Sodium ferrocyanide MSDS Archived 2010-05-17 at the Wayback Machine

[toxic-2] "Toxicological evaluation of some food additives including anticaking agents, antimicrobials, antioxidants, emulsifiers and thickening agents". World Health Organization, Geneva. 1974. Retrieved 18 May 2009.

[Holl-3] Holleman, A. F.; Wiberg, E. (2001). Inorganic Chemistry. San Diego: Academic Press. ISBN 0-12-352651-5.

[4] "Prussian blue". Encyclopædia Britannica. Retrieved 18 May 2009.

[5] Peter Aggett, Fernando Aguilar, Riccardo Crebelli, Birgit Dusemund, Metka Filipič, Maria Jose Frutos, Pierre Galtier, David Gott, Ursula Gundert‐Remy, Gunter Georg Kuhnle, Claude Lambré, Jean‐Charles Leblanc, Inger Therese Lillegaard, Peter Moldeus, Alicja Mortensen, Agneta Oskarsson, Ivan Stankovic, Ine Waalkens‐Berendsen, Rudolf Antonius Woutersen, Matthew Wright and Maged Younes. (2018). "Re‐evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide (E 536) and calcium ferrocyanide (E 538) as food additives". EFSA Journal. 16 (7): 5374. doi:10.2903/j.efsa.2018.5374.CS1 maint: multiple names: authors list (link)

[Ullmann-6] Gail, E.; Gos, S.; Kulzer, R.; Lorösch, J.; Rubo, A.; Sauer, M.; Kellens, R.; Reddy, J.; Steier, N. (2011). "Cyano Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_159.pub3.

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