This MedLibrary.org supplementary page on Chromium trioxide is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
| Chromium trioxide | |
|---|---|
-oxid.jpg) |
|
| IUPAC name | Chromium(VI) oxide |
| Other names | Chromium trioxide |
| Identifiers | |
| CAS number | 1333-82-0 |
| RTECS number | GB6650000 |
| SMILES |
|
| Properties | |
| Molecular formula | CrO3 |
| Molar mass | 99.994 g/mol |
| Appearance | Dark red solid |
| Density | 2.70 g/cm3, solid |
| Melting point |
197 °C |
| Boiling point |
250 °C, decomposes |
| Solubility in water | 63 g/100 mL |
| Hazards | |
| EU classification | Oxidizer (O), very toxic (T+), dangerous for the environment (N) |
| NFPA 704 |
 0
3
1
OX
|
| R-phrases | R45 R46 R9 R24/25 R26 R35 R42/43 R48/23 R62 R50/53 |
| S-phrases | S53 S45 S60 S61 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references |
|
The acid anhydride of chromic acid, CrO3, is chromium trioxide or chromium(VI) oxide; industrially, this compound is sometimes sold as "chromic acid".1 This compound is an intensely-colored dark red/orange brown, water-soluble, granular solid which is stable by itself, but is a strong oxidant which will react when mixed with many things that can be oxidized. Ethanol, for example, will ignite on contact with it.
Contents |
Production
Chromium trioxide is produced commercially by the reaction of sodium dichromate with concentrated sulfuric acid.1
Structure and chemistry
Chromium trioxide consists of chains of tetrahedrally coordinated chromium atoms that share vertices. Each chromium atom therefore has "half share of two oxygen atoms" and two oxygen atoms that are not shared, giving an overall stoichiometry of 1:3.2
Chromium trioxide decomposes above 197°C liberating oxygen eventually giving Cr2O3. The reaction of chromium trioxide with organic substances is potentially explosive. In spite of this, CrO3 is used in organic chemistry as an oxidant, often dissolved in acetic acid,2 or acetone in the case of the Jones oxidation.
Safety
Chromium trioxide is highly toxic, corrosive, and carcinogenic.3
Chromium trioxide may cause cancer and/or heritable genetic damage. It is explosive when mixed with combustible material. It is toxic in contact with skin and if swallowed and very toxic by inhalation. CrO3 causes severe burns and may cause sensitisation by inhalation and skin contact. It is also systemically toxic: danger of serious damage to health by prolonged exposure through inhalation. There is a possible risk of impaired fertility. CrO3 is very toxic to aquatic organisms and may cause long-term adverse effects in the aquatic environment.
References
- ^ a b "Chromium Trioxide". Chemicalland21.
- ^ a b Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999), Advanced Inorganic Chemistry (6th ed.), New York: Wiley-Interscience, ISBN 0-471-19957-5
- ^ "Chromium Trioxide (MSDS)". J. T. Baker. Retrieved on 2007-09-13.
Wikipedia content modification information:
- This page was last modified on 5 November 2008, at 20:49.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Chromium trioxide".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.