Cobalt (II) oxalate
Structural formula | |||||||||||||||||||
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General | |||||||||||||||||||
Surname | Cobalt (II) oxalate | ||||||||||||||||||
other names |
Cobalt oxalate
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Molecular formula | C 2 CoO 4 | ||||||||||||||||||
Brief description |
pink solid |
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properties | |||||||||||||||||||
Molar mass | 146.95 g mol −1 | ||||||||||||||||||
Physical state |
firmly |
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density |
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Melting point |
229–231 ° C (decomposition) |
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solubility |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Cobalt (II) oxalate is a chemical compound of cobalt from the group of oxalates .
Extraction and presentation
Cobalt (II) oxalate dihydrate can be obtained by reacting cobalt chloride with ammonium oxalate. It is also possible to display it by reacting an aqueous solution of cobalt (II) bromide with oxalic acid .
properties
The compound is a flammable, hardly inflammable, crystalline, pink solid that is practically insoluble in water. It decomposes when heated above 300 ° C.
It occurs in two allotropic crystal structures . It has a monoclinic crystal structure with the space group C 2 / c (space group no. 15) , the other an orthorhombic crystal structure with the space group Cccm (space group no. 66) . Both structures are formed by identical infinite chains of CoC 2 O 4 -2H 2 O units. The difference between them lies in the relative displacement of neighboring chains along the B-axis. The elimination of the water of crystallization of the dihydrates begins at 145 ° C.
use
Cobalt (II) oxalate is mainly used to make cobalt powder. The yellowish-pink tetrahydrate is used in the manufacture of catalysts .
Individual evidence
- ↑ a b c d e f Entry on cobalt (II) oxalate in the GESTIS substance database of the IFA , accessed on January 17, 2019(JavaScript required) .
- ↑ a b Datasheet Cobalt (II) oxalate dihydrate, Puratronic®, 99.995% (metals basis) from AlfaAesar, accessed on January 17, 2019 ( PDF )(JavaScript required) .
- ↑ Dale L. Perry: Handbook of Inorganic Compounds . CRC Press, 2016, ISBN 978-1-4398-1462-8 , pp. 478 ( limited preview in Google Book search).
- ↑ Data sheet Cobalt (II) oxalate, anhydrous, 98% from AlfaAesar, accessed on January 17, 2019 ( PDF )(JavaScript required) .
- ↑ Huiling Du, Jianzhong Wang et al. a .: Preparation of cobalt oxalate powders with the presence of a pulsed electromagnetic field. In: Powder Technology. 199, 2010, p. 149, doi: 10.1016 / j.powtec.2009.12.015 .
- ↑ a b E. Romero, ME Mendoza, R. Escudero: Weak ferromagnetism in cobalt oxalate crystals. In: physica status solidi. 248, 2011, p. 1519, doi: 10.1002 / pssb.201046402 .
- ^ Ullmann's Encyclopedia of Industrial Chemistry . John Wiley & Sons, 2003, ISBN 978-3-527-30385-4 , pp. 785 ( limited preview in Google Book search).
- ↑ D. Nicholls: The Chemistry of Iron, Cobalt and Nickel Comprehensive Inorganic Chemistry . Elsevier, 2013, ISBN 978-1-4831-4643-0 , pp. 1072 ( limited preview in Google Book search).