Iron (II) hydroxide

Crystal structure
	__ Fe 2+ __ OH -
General
Surname	Iron (II) hydroxide
other names	Iron dihydroxide; Iron hydroxide (ambiguous);
Ratio formula	Fe (OH) 2
Brief description	white solid
External identifiers / databases
EC number	242-456-5
ECHA InfoCard	100,038,581
PubChem	10129897
Wikidata	Q804525
properties
Molar mass	89.86 g mol −1
Physical state	firmly
density	3.4 g cm −3
solubility	soluble in hydrochloric acid , concentrated sulfuric acid and hydrofluoric acid ; practically insoluble in water (0.99 mg l −1 at 20 ° C);
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 .

Iron (II) hydroxide is an inorganic chemical compound of iron from the group of hydroxides .

Extraction and presentation

Iron (II) hydroxide is obtained by precipitation from iron (II) salt solutions with the exclusion of oxygen (e.g. ammonium iron (II) sulfate solution with sodium hydroxide solution ). The white flaky precipitate quickly turns dark with the formation of red-brown iron (III) hydroxide .

It is also formed as an intermediate in the rusting of iron, which is a result of atmospheric oxygen through hydrous iron (III) hydroxide FeO (OH) further red-brown iron (III) oxide or a shortage of oxygen to green magnetite reacted hydrate and black magnetite becomes.

properties

Iron (II) hydroxide is an almost white, unstable solid in air with a slight, greenish tinge. It burns with sparks when it is scattered in the air. If oxygen is excluded , pure preparations , especially nickel , copper and cobalt-free, are completely stable in contact with potassium chloride solution below 100 ° C. The compound has a crystal structure of the cadmium (II) hydroxide type with the space group P 3 m 1 (space group no.164) ( lattice parameter a = 325.8 pm, c = 460.5 pm). Iron (II) hydroxide is amphoteric and dissolves in concentrated alkalis with the formation of blue-green hydroxoferrates (II), e.g. B. Na ₄ [Fe (OH) ₆ ] . Template: room group / 164

Individual evidence

↑ ^a ^b ^c Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1646.
^ ^A ^b Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 456 ( limited preview in Google Book search).
↑ K. Rauschert, J. Voigt, I. Wilke, K-Th. Wilke: Chemical tables and calculation tables for analytical practice . 11th edition. Europa-Lehrmittel, 2000, ISBN 978-3-8085-5450-0 , p. 171 .
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
^ ^A ^b Erwin Riedel: Inorganic Chemistry . Walter de Gruyter, 2004, ISBN 3-11-018168-1 , p. 826 ( limited preview in Google Book search).
^ Arnold F. Holleman, Nils Wiberg: Textbook of Inorganic Chemistry , 102nd Edition, de Gruyter, Berlin 2007, p. 1654.
↑ Horst Briehl: Chemistry of materials . Springer, 2007, ISBN 3-8351-0223-0 , pp. 111 ( limited preview in Google Book search).
^ Udo Schwertmann, Rochelle M. Cornell: Iron Oxides in the Laboratory . John Wiley & Sons, 2000, ISBN 978-3-527-29669-9 , pp. 10 ( books.google.de ).

[brauer-1] Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1646.

[Lax-2] A ^b Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 456 ( limited preview in Google Book search).

[3] K. Rauschert, J. Voigt, I. Wilke, K-Th. Wilke: Chemical tables and calculation tables for analytical practice . 11th edition. Europa-Lehrmittel, 2000, ISBN 978-3-8085-5450-0 , p. 171 .

[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.

[Erwin_Riedel-5] A ^b Erwin Riedel: Inorganic Chemistry . Walter de Gruyter, 2004, ISBN 3-11-018168-1 , p. 826 ( limited preview in Google Book search).

[HoWi2007-6] Arnold F. Holleman, Nils Wiberg: Textbook of Inorganic Chemistry , 102nd Edition, de Gruyter, Berlin 2007, p. 1654.

[Horst_Briehl-7] Horst Briehl: Chemistry of materials . Springer, 2007, ISBN 3-8351-0223-0 , pp. 111 ( limited preview in Google Book search).

[8] Udo Schwertmann, Rochelle M. Cornell: Iron Oxides in the Laboratory . John Wiley & Sons, 2000, ISBN 978-3-527-29669-9 , pp. 10 ( books.google.de ).