|IUPAC name||Chromium(VI) oxide|
|Other names||Chromium trioxide|
|Molar mass||99.994 g/mol|
|Appearance||Dark red solid|
|Density||2.70 g/cm3, solid|
250 °C, decomposes
|Solubility in water||63 g/100 mL|
|EU classification||Oxidizer (O), very toxic (T+), dangerous for the environment (N)|
| Except where noted otherwise, data are given for|
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references
The acid anhydride of chromic acid is chromium trioxide or chromium(VI) oxide; industrially, this compound is sometimes sold as "chromic acid". 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.
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.
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, or acetone in the case of the Jones oxidation.
Chromium trioxide is highly toxic, corrosive, and carcinogenic.