Cobalt (II) hydroxide

Crystal structure
	__ Co 2+ __ OH -
General
Surname	Cobalt (II) hydroxide
other names	Cobalt dihydroxide
Ratio formula	Co (OH) 2
Brief description	pink powder
External identifiers / databases
EC number	244-166-4
ECHA InfoCard	100.040.136
PubChem	62748
Wikidata	Q417152
properties
Molar mass	92.95 g mol −1
Physical state	firmly
density	3.597 g cm −3 (25 ° C)
solubility	poorly soluble in water; soluble in concentrated alkalis;
safety instructions
H and P phrases	H: 302 + 332-317-319-334-351-410
	P: 261-273-280-284-304 + 340 + 312-342 + 311
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Cobalt (II) hydroxide is a chemical compound of cobalt from the group of hydroxides .

Extraction and presentation

pink cobalt (II) hydroxide

blue cobalt (II) hydroxide

Cobalt (II) hydroxide is precipitated from cobalt (II) solutions by alkali lye, depending on the water content, as an initially unstable blue, later pinkish-red precipitate.

{\ displaystyle \ mathrm {Co (NO_ {3}) _ {2} \ cdot 6H_ {2} O + 2 \ KOH \ longrightarrow Co (OH) _ {2} +2 \ KNO_ {3} +6 \ H_ { 2} O}}

properties

Cobalt (II) hydroxide is a non- amphoteric , pink solid with a cadmium iodide crystal structure. It decomposes at 168 ° C in vacuo to cobalt (II) oxide and is oxidized to cobalt (III) hydroxide by air . Thermal decomposition in air at over 300 ° C results in cobalt (II, III) oxide . When stored in air, the brown cobalt (III) oxide hydrate is formed. Cobalt (II) hydroxide is soluble in concentrated alkalis, whereby deep blue tetrahydroxo-cobaltate (II) ions ([Co (OH) ₄ ] ²⁻ ) are formed.

With 3Co (OH) ₂ · 2H ₂ O there is also a hydrate. This is a blue powder. Its crystal structure is a layer lattice consisting of hydroxide layers of the brucite type, in which the distance between the layers is widened by incorporating an intermediate layer of water.

use

Cobalt (II) hydroxide is used as an intermediate in the production of cobalt.

Individual evidence

↑ ^a ^b ^c ^d Data sheet Cobalt (II) hydroxide, technical grade, 95% from Sigma-Aldrich , accessed on July 9, 2012 ( PDF ).
↑ ^a ^b ^c ^d Erwin Riedel, Christoph Janiak: Inorganische Chemie . Walter de Gruyter, 2011, ISBN 3-11-022566-2 , p. 860 ( limited preview in Google Book search).
↑ ^a ^b Entry on cobalt dihydroxide in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
^ ^A ^b ^c Karl-Heinz Lautenschläger, Werner Schröter: Pocket book of chemistry . Harri Deutsch Verlag, 2008, ISBN 978-3-8171-1761-1 , pp. 582 ( limited preview in Google Book search).
^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1554.
↑ Pradyot Patnaik: Handbook of Inorganic Chemical Compounds. McGraw-Hill Professional. 2003, ISBN 0-07-049439-8 , p. 243.
↑ 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. 1665.
^ Karl-Heinz Lautenschläger, Werner Schröter: Extractive Metallurgy of Nickel, Cobalt and Platinum Group Metals . Elsevier, 2011, ISBN 0-08-096810-4 , pp. 384 ( limited preview in Google Book Search).

[Sigma-1] Data sheet Cobalt (II) hydroxide, technical grade, 95% from Sigma-Aldrich , accessed on July 9, 2012 ( PDF ).

[Erwin_Riedel,Christoph_Janiak-2] Erwin Riedel, Christoph Janiak: Inorganische Chemie . Walter de Gruyter, 2011, ISBN 3-11-022566-2 , p. 860 ( limited preview in Google Book search).

[GESTIS-3] Entry on cobalt dihydroxide in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .

[Karl-Heinz_Lautenschläger,_Werner_Schröter-4] A ^b ^c Karl-Heinz Lautenschläger, Werner Schröter: Pocket book of chemistry . Harri Deutsch Verlag, 2008, ISBN 978-3-8171-1761-1 , pp. 582 ( limited preview in Google Book search).

[Arnold_F._Holleman,_Egon_Wiberg-5] AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1554.

[Patnaik,_Pradyot-6] Pradyot Patnaik: Handbook of Inorganic Chemical Compounds. McGraw-Hill Professional. 2003, ISBN 0-07-049439-8 , p. 243.

[brauer-7] 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. 1665.

[von_Karl-Heinz_Lautenschläger,Werner_Schröter-8] Karl-Heinz Lautenschläger, Werner Schröter: Extractive Metallurgy of Nickel, Cobalt and Platinum Group Metals . Elsevier, 2011, ISBN 0-08-096810-4 , pp. 384 ( limited preview in Google Book Search).