Chromium(III) hydroxide
Chromium(III) hydroxide is a gelatinous green inorganic compound with the chemical formula Cr(OH)3. It is a polymer with an undefined structure and low solubility. It is amphoteric, dissolving in both strong alkalis and strong acids.[2]
- In alkali: Cr(OH)3 + OH− → CrO−
2 + 2 H2O - In acid: Cr(OH)3(OH2)3 + 3 H+ → Cr(OH
2)3+
6
_hydroxide.png.webp) | |
| Names | |
|---|---|
| IUPAC name
Chromium(3+) hydroxide | |
| Identifiers | |
3D model (JSmol) |
|
| ECHA InfoCard | 100.013.781  |
PubChem CID |
|
| RTECS number |
|
| UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
| Properties | |
| Cr(OH)3 | |
| Molar mass | 103.02 g/mol |
| Appearance | green, gelatinous precipitate |
| Density | 3.11 g/cm3 |
| insoluble | |
| Hazards | |
| NIOSH (US health exposure limits): | |
PEL (Permissible) |
TWA 1 mg/m3[1] |
REL (Recommended) |
TWA 0.5 mg/m3[1] |
IDLH (Immediate danger) |
250 mg/m3[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
It is used as a pigment, as a mordant, and as a catalyst for organic reactions.[3]
It is manufactured by adding a solution of ammonium hydroxide to a solution of chromium salt.
Pure Cr(OH)3 is as yet (2020) unknown among the mineral species. However, three natural polymorphs of the oxyhydroxide, CrO(OH), are known: bracewellite, grimaldiite and guyanaite.[4][5][6][7]
References
- NIOSH Pocket Guide to Chemical Hazards. "#0141". National Institute for Occupational Safety and Health (NIOSH).
- Rai, Dhanpat; Sass, Bruce M.; Moore, Dean A. "Chromium(III) hydrolysis constants and solubility of chromium(III) hydroxide" Inorganic Chemistry 1987, volume 26, pp. 345-9. doi:10.1021/ic00250a002
- Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1985). "Chromium". Lehrbuch der Anorganischen Chemie (in German) (91–100 ed.). Walter de Gruyter. pp. 1081–1095. ISBN 3-11-007511-3.
- https://www.mindat.org/min-748.html
- https://www.mindat.org/min-1750.html
- https://www.mindat.org/min-1783.html
- https://www.ima-mineralogy.org/Minlist.htm
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.