Chromium (VI) peroxide

Structural formula
General
Surname	Chromium (VI) peroxide
other names	Chromium peroxide; Blue butterfly;
Molecular formula	CrO 5
External identifiers / databases
PubChem	22222816
ChemSpider	21865108
Wikidata	Q2034517
properties
Molar mass	131.99 g mol −1
safety instructions
H and P phrases	H: 350i-317-410
	P: ?
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Chromium (VI) peroxide is a chemical compound of chromium from the group of peroxides .

Extraction and presentation

Chromium (VI) peroxide can be obtained by reacting dichromates in a sulfuric or nitric acid solution with hydrogen peroxide .

{\ displaystyle \ mathrm {Cr_ {2} O_ {7} ^ {2 -} + 4 \ H_ {2} O_ {2} +2 \ H ^ {+} \ longrightarrow 2 \ [CrO (O_ {2}) _ {2}] + 5 \ H_ {2} O}}

properties

Chromium (VI) peroxide is a deep blue compound that is soluble in water, ethers and esters. It is unstable in water and rapidly decomposes with the oxidation of the hydrogen peroxide, the color of the solution changing to green or purple. The blue solution is not pure chromium (VI) peroxide, but a hydroxo complex. The compound also forms complexes with other compounds such as pyridine and diethyl ether .

use

The formation of blue chromium (VI) peroxide is used as a detection reaction. For this purpose, dilute nitric acid is mixed with hydrogen peroxide and covered with diethyl ether . The ether serves as a stabilizer, otherwise the chromium peroxide will decompose again after a short time with evolution of oxygen.

Aqueous solution of chromium (VI) peroxide
A very dilute solution of chromium (VI) peroxide
Chromium (VI) peroxide stabilized in ether (above) and aqueous chromium (III) solution (below).

Individual evidence

↑ Entry on chromium (VI) compounds in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entry Chromium (VI) compounds, with the exception of barium chromate and of compounds specified elsewhere in this Annex in the Classification and Labeling inventory of the European Chemicals Agency (ECHA), accessed on August 14, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
^ ^A ^b Erwin Riedel, Christoph Janiak: Inorganische Chemie . Walter de Gruyter, 2011, ISBN 978-3-11-022567-9 , pp. 915 ( limited preview in Google Book search).
↑ Hans P. Latscha, Helmut Klein: Analytical Chemistry Chemistry - Basic Knowledge III . Springer-Verlag, 2013, ISBN 978-3-642-97604-9 , pp. 84 ( limited preview in Google Book search).
↑ chemieunterricht.de: Prof. Blum's media offer: catalysts and enzymes , accessed on May 25, 2015

^ Ronald Rich: Inorganic Reactions in Water . Springer, 2007, ISBN 978-3-540-73962-3 , pp. 115 ( limited preview in Google Book search).

↑ Günter Grampp, Stephan Landgraf, Tomasz Wesierski, Beata Jankowska, Ewa Kalisz, Dana-Maria Sabou, Boryana Mladenova: Kinetics of the Formation of the Blue Complex CrO (O ₂ ) ₂ Formed by Dichromate and H ₂ O ₂ in Acid Solutions. A Stopped-Flow Investigation Using Rapid-Scan UV-VIS Detection. In: Monthly books for chemistry / Chemical Monthly. 133, 2002, p. 1363, doi: 10.1007 / s00706-002-0488-5 .

↑ Götz Bucher, Michaela Kampe, Julius F. Roelcke: Peroxides and Chromium Compounds - The Ether Test for Identity. In: Journal of Nature Research B . 60, 2005, pp. 1–6 ( PDF , free full text).

[1] Entry on chromium (VI) compounds in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .

[CLP_100.240.768-2] Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entry Chromium (VI) compounds, with the exception of barium chromate and of compounds specified elsewhere in this Annex in the Classification and Labeling inventory of the European Chemicals Agency (ECHA), accessed on August 14, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[Erwin_Riedel,_Christoph_Janiak-3] A ^b Erwin Riedel, Christoph Janiak: Inorganische Chemie . Walter de Gruyter, 2011, ISBN 978-3-11-022567-9 , pp. 915 ( limited preview in Google Book search).

[Hans_P._Latscha,_Helmut_Klein-4] Hans P. Latscha, Helmut Klein: Analytical Chemistry Chemistry - Basic Knowledge III . Springer-Verlag, 2013, ISBN 978-3-642-97604-9 , pp. 84 ( limited preview in Google Book search).

[chemieunterricht-5] unterricht.de: Prof. Blum's media offer: catalysts and enzymes , accessed on May 25, 2015

[Ronald_Rich-6] Ronald Rich: Inorganic Reactions in Water . Springer, 2007, ISBN 978-3-540-73962-3 , pp. 115 ( limited preview in Google Book search).

[DOI10.1007/s00706-002-0488-5-7] Günter Grampp, Stephan Landgraf, Tomasz Wesierski, Beata Jankowska, Ewa Kalisz, Dana-Maria Sabou, Boryana Mladenova: Kinetics of the Formation of the Blue Complex CrO (O ₂ ) ₂ Formed by Dichromate and H ₂ O ₂ in Acid Solutions. A Stopped-Flow Investigation Using Rapid-Scan UV-VIS Detection. In: Monthly books for chemistry / Chemical Monthly. 133, 2002, p. 1363, doi: 10.1007 / s00706-002-0488-5 .

[Peroxides-8] Götz Bucher, Michaela Kampe, Julius F. Roelcke: Peroxides and Chromium Compounds - The Ether Test for Identity. In: Journal of Nature Research B . 60, 2005, pp. 1–6 ( PDF , free full text).