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Names | |
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IUPAC name Chromium(3+) hydroxide | |
Identifiers | |
3D model (JSmol) |
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ChemSpider | |
ECHA InfoCard | 100.013.781 |
PubChem CID | |
RTECS number |
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UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
Cr(OH)3 | |
Molar mass | 103.017 g·mol−1 |
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). |
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]
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.[ citation needed ]
Pure Cr(OH)3 is as yet (2020) unknown among the mineral species. However, three natural polymorphs of the chromium(III) oxide hydroxide, CrO(OH), are known: bracewellite, grimaldiite and guyanaite. [4] [5] [6] [7]