Sodium ferrocyanide: Difference between revisions
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'''Sodium ferrocyanide''' is the sodium [[Salt (chemistry)|salt]] of the [[complex (chemistry)|coordination compound]] of formula [Fe(CN)<sub>6</sub>]<sup>4−</sup>. In its [[Hydrate|hydrous]] form, Na<sub>4</sub>Fe(CN)<sub>6</sub> · 10 H<sub>2</sub>O (sodium ferrocyanide decahydrate), it is sometimes known as '''yellow prussiate of soda'''. It is a yellow [[crystal]]line solid that is soluble in water and insoluble in [[ethanol|alcohol]]. The yellow color is the color of ferrocyanide anion. Despite the presence of the [[cyanide]] [[ligand]]s, sodium ferrocyanide has low [[toxicity]] (acceptable daily intake 0–0.025 mg/kg body weight<ref name=toxic/>). The [[ferrocyanide]]s are less toxic than many salts of cyanide, because they tend not to release free cyanide.<ref name=Holl>{{ cite book |author1=Holleman, A. F. |author2=Wiberg, E. | title = Inorganic Chemistry | publisher = Academic Press | location = San Diego | year = 2001 | isbn = 0-12-352651-5 }}</ref> However, like all ferrocyanide salt solutions, addition of an acid can result in the production of hydrogen cyanide gas, which is toxic. |
'''Sodium ferrocyanide''' is the sodium [[Salt (chemistry)|salt]] of the [[complex (chemistry)|coordination compound]] of formula [Fe(CN)<sub>6</sub>]<sup>4−</sup>. In its [[Hydrate|hydrous]] form, Na<sub>4</sub>Fe(CN)<sub>6</sub> · 10 H<sub>2</sub>O ([[sodium]] [[ferrocyanide]] [[decahydrate]]), it is sometimes known as '''yellow [[prussiate]] of soda'''. It is a yellow [[crystal]]line solid that is soluble in water and insoluble in [[ethanol|alcohol]]. The yellow color is the color of ferrocyanide [[anion]]. Despite the presence of the [[cyanide]] [[ligand]]s, sodium ferrocyanide has low [[toxicity]] (acceptable daily intake 0–0.025 mg/kg body weight<ref name=toxic/>). The [[ferrocyanide]]s are less toxic than many salts of cyanide, because they tend not to release free cyanide.<ref name=Holl>{{ cite book |author1=Holleman, A. F. |author2=Wiberg, E. | title = Inorganic Chemistry | publisher = Academic Press | location = San Diego | year = 2001 | isbn = 0-12-352651-5 }}</ref> However, like all ferrocyanide salt solutions, addition of an acid can result in the production of [[hydrogen cyanide]] gas, which is toxic. |
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==Uses== |
==Uses== |
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Sodium ferrocyanide is a chemical additive known as [[E number]] '''E535''' in the [[European Union|EU]]. It is added to road and food grade [[salt]] as an [[anticaking agent]].<ref name=toxic>{{cite web| url =http://www.inchem.org/documents/jecfa/jecmono/v05je02.htm|title = Toxicological evaluation of some food additives including anticaking agents, antimicrobials, antioxidants, emulsifiers and thickening agents| publisher = World Health Organization, Geneva| year = 1974|accessdate = 18 May 2009}}</ref> When combined with iron, it converts to a deep blue pigment called [[Prussian blue]].<ref>{{cite web| title = Prussian blue |publisher = Encyclopædia Britannica|accessdate =18 May 2009 |url =http://www.britannica.com/EBchecked/topic/480982/Prussian-blue}}</ref> It is used as a stabilizer for the coating on [[welding]] rods. In the [[petroleum]] industry, it is used for removal of [[mercaptan]]s. |
Sodium ferrocyanide is a chemical additive known as [[E number]] '''E535''' in the [[European Union|EU]]. It is added to road and food grade [[salt]] as an [[anticaking agent]].<ref name=toxic>{{cite web| url =http://www.inchem.org/documents/jecfa/jecmono/v05je02.htm|title = Toxicological evaluation of some food additives including anticaking agents, antimicrobials, antioxidants, emulsifiers and thickening agents| publisher = World Health Organization, Geneva| year = 1974|accessdate = 18 May 2009}}</ref> When combined with iron, it converts to a deep blue pigment called [[Prussian blue]].<ref>{{cite web| title = Prussian blue |publisher = Encyclopædia Britannica|accessdate =18 May 2009 |url =http://www.britannica.com/EBchecked/topic/480982/Prussian-blue}}</ref> It is used as a stabilizer for the coating on [[welding]] rods. In the [[petroleum]] industry, it is used for removal of [[mercaptan]]s. |
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In the EU, ferrocyanides (E 535–538) were, as of 2018, solely authorised in two food categories as salt |
In the EU, ferrocyanides (E 535–538) were, as of 2018, solely authorised in two food categories as [[salt substitute]]s. [[Kidney]]s are the organ for ferrocyanide [[toxicity]].<ref>{{cite journal |last1=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. |title=Re‐evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide (E 536) and calcium ferrocyanide (E 538) as food additives |journal=EFSA Journal |date=2018 |volume=16 |issue=7 |page=5374 |doi=10.2903/j.efsa.2018.5374 |url=https://www.efsa.europa.eu/en/efsajournal/pub/5374}}</ref> |
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==Production== |
==Production== |
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Sodium ferrocyanide is produced industrially from [[hydrogen cyanide]], [[ferrous chloride]], and [[calcium hydroxide]], the combination of which affords Ca<sub>2</sub>[Fe(CN)<sub>6</sub>]<sup>.</sup>11H<sub>2</sub>O. A solution of this salt is then treated with sodium salts to precipitate the mixed calcium-sodium salt CaNa<sub>2</sub>[Fe(CN)<sub>6</sub>], which in turn is treated with sodium carbonate to give the tetrasodium salt.<ref name=Ullmann>{{ cite encyclopedia |author1=Gail, E. |author2=Gos, S. |author3=Kulzer, R. |author4=Lorösch, J. |author5=Rubo, A. |author6=Sauer, M. |author7=Kellens, R. |author8=Reddy, J. |author9=Steier, N. |author10=Hasenpusch, W. | title = Cyano Compounds, Inorganic | encyclopedia = Ullmann's Encyclopedia in Industrial Chemistry | year = 2011 | publisher = Wiley-VCH | location = Weinheim | doi = 10.1002/14356007.a08_159.pub3 }}</ref> |
Sodium ferrocyanide is produced industrially from [[hydrogen cyanide]], [[ferrous chloride]], and [[calcium hydroxide]], the combination of which affords Ca<sub>2</sub>[Fe(CN)<sub>6</sub>]<sup>.</sup>11H<sub>2</sub>O. A solution of this salt is then treated with sodium salts to precipitate the mixed calcium-sodium salt CaNa<sub>2</sub>[Fe(CN)<sub>6</sub>], which in turn is treated with [[sodium carbonate]] to give the tetrasodium salt.<ref name=Ullmann>{{ cite encyclopedia |author1=Gail, E. |author2=Gos, S. |author3=Kulzer, R. |author4=Lorösch, J. |author5=Rubo, A. |author6=Sauer, M. |author7=Kellens, R. |author8=Reddy, J. |author9=Steier, N. |author10=Hasenpusch, W. | title = Cyano Compounds, Inorganic | encyclopedia = Ullmann's Encyclopedia in Industrial Chemistry | year = 2011 | publisher = Wiley-VCH | location = Weinheim | doi = 10.1002/14356007.a08_159.pub3 }}</ref> |
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==References== |
==References== |
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Revision as of 05:59, 24 December 2018
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| Names | |
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| IUPAC name
Tetrasodium [hexacyanoferrate(II)]
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| Other names
Yellow prussiate of soda (YPS), Tetrasodium hexacyanoferrate, Gelbnatron, Ferrocyannatrium, sodium hexacyanoferrate(II), Yellow blood salt[citation needed]
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| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.033.696 |
| EC Number |
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| E number | E535 (acidity regulators, ...) |
PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| 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) |
| 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)
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1.530 |
| Structure | |
| monoclinic | |
| Related compounds | |
Other anions
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Sodium ferricyanide (Red prussiate of soda) |
Other cations
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Potassium ferrocyanide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium ferrocyanide is the sodium salt of the coordination compound of formula [Fe(CN)6]4−. In its hydrous form, Na4Fe(CN)6 · 10 H2O (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
Sodium ferrocyanide is a chemical additive known as E number E535 in the EU. It is added to road and food grade salt as an anticaking agent.[2] When combined with iron, it converts to a deep blue pigment called Prussian blue.[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 authorised in two food categories as salt substitutes. Kidneys are the organ for ferrocyanide toxicity.[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
- ^ a b "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.
{{cite journal}}: 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.; Hasenpusch, W. (2011). "Cyano Compounds, Inorganic". Ullmann's Encyclopedia in Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_159.pub3.