Calcium hexacyanidoferrate (II)

Structural formula
General
Surname	Calcium hexacyanidoferrate (II)
other names	Calcium hexacyanoferrate (II); Calcium ferrocyanide; E 538 ;
Molecular formula	Ca 2 [Fe (CN) 6 ]
Brief description	yellow solid
External identifiers / databases
EC number	237-508-9
ECHA InfoCard	100.034.085
PubChem	166920
ChemSpider	21160188
Wikidata	Q1026348
properties
Molar mass	292.11 g mol −1
Physical state	firmly
density	1.68 g cm −3
solubility	very soluble in water; practically insoluble in ethanol ;
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Calcium hexacyanidoferrate (II) ( calcium ferrocyanide , outdated calcium hexacyanoferrate (II) ) is a salt with the constitutional formula Ca ₂ [Fe (CN) ₆ ].

Extraction and presentation

Calcium hexacyanidoferrate can be obtained by reacting sodium hexacyanidoferrate (II) with calcium hydroxide .

{\ displaystyle {\ ce {Na4 [Fe (CN) 6] + 2Ca (OH) 2 -> Ca2 [Fe (CN) 6] + 4Na (OH)}}}

use

It is used as a release agent in food technology. When exposed to strong acids, the hydrogen cyanide, which is strongly bound to the iron, can be released. For the bulked set of all ferrocyanides one was permitted daily dose of 0,025 milligrams per kilogram of body weight set. It is approved in the EU as a food additive with the number E 538 with a maximum quantity restriction of up to 20 milligrams per kilogram for table salt and table salt substitutes .

Individual evidence

↑ Entry on E 538: Calcium ferrocyanide in the European database for food additives, accessed on June 27, 2020.
↑ Entry on Hexacyanidoferrate. In: Römpp Online . Georg Thieme Verlag, accessed on June 6, 2014.
↑ ^a ^b ^c ^d William M. Haynes: CRC Handbook of Chemistry and Physics, 96th Edition . CRC Press, 2015, ISBN 978-1-4822-6097-7 , pp. 55 ( limited preview in Google Book search).
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ Re ‐ evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide: Re ‐ evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide , doi : 10.2903 / j.efsa.2018.5374 , accessed on December 21, 2019
↑ Restricted additives , Annex 4 (to § 5 Paragraph 1 and § 7) of the Additive Admissions Ordinance

[E-Nummer538-1] Entry on E 538: Calcium ferrocyanide in the European database for food additives, accessed on June 27, 2020.

[roempp-2] Entry on Hexacyanidoferrate. In: Römpp Online . Georg Thieme Verlag, accessed on June 6, 2014.

[William_M._Haynes-3] William M. Haynes: CRC Handbook of Chemistry and Physics, 96th Edition . CRC Press, 2015, ISBN 978-1-4822-6097-7 , pp. 55 ( limited preview in Google Book search).

[NV-4] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[efsa.europa.eu-5] Re ‐ evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide: Re ‐ evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide , doi : 10.2903 / j.efsa.2018.5374 , accessed on December 21, 2019

[6] Restricted additives , Annex 4 (to § 5 Paragraph 1 and § 7) of the Additive Admissions Ordinance