Chromium(III) hydroxide

Source: Wikipedia, the free encyclopedia.
Chromium(III) hydroxide
Names
IUPAC name
Chromium(3+) hydroxide
Systematic IUPAC name
Idrossido Cromoso
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
100.013.781 Edit this at Wikidata
RTECS number
  • GB2670000
UNII
  • InChI=1S/Cr.3H2O/h;3*1H2
    Key: LXMQZGGLHVSEBA-UHFFFAOYSA-N
SMILES
  • ionic form: [OH-].[OH-].[OH-].[Cr+++]
  • coordination form: O[Cr](O)O
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).

Chromium(III) hydroxide is a gelatinous green

amphoteric, dissolving in both strong alkalis and strong acids.[2]

In alkali: Cr(OH)3 + OH → CrO2 + 2 H2O
In acid: Cr(OH)3(OH2)3 + 3 H+ → Cr(OH2)63+

It is used 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 oxyhydroxide, CrO(OH), are known: bracewellite, grimaldiite and guyanaite.[4][5][6][7]

References

  1. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0141". National Institute for Occupational Safety and Health (NIOSH).
  2. .
  3. ^ "Bracewellite".
  4. ^ "Grimaldiite".
  5. ^ "Guyanaite".
  6. ^ "List of Minerals". 21 March 2011.