Chromium(III) sulfate

From Wikipedia, the free encyclopedia
  (Redirected from Chromium sulfate)
Jump to: navigation, search
Chromium(III) sulfate
Chromium(III) sulfate.jpg
Names
IUPAC name
Chromium(III) sulfate
Other names
Basic chromium sulfate, chromic sulfate
Identifiers
10101-53-8 YesY
13520-66-6 (dodecahydrate) N
ChemSpider 21241287 N
Jmol-3D images Image
PubChem 24930
UNII Y0C99N5TMZ YesY
Properties
Cr2(SO4)3 • 12H2O
Molar mass 392.16 g/mol
608.363 g/mol (dodecahydrate)

716.45 g/mol (octadecahydrate)

Appearance reddish-brown crystals (anhydrous), purple crystals (hydrated)
Density 3.10 g/cm3 (anhydrous)
1.86 g/cm3 (pentadecahydrate)
1.709 g/cm3 (octadecahydrate)
Melting point 90 °C
Boiling point decomposes to chromic acid
insoluble (anhydrous)
soluble (hydrated)
Solubility soluble in alcohol
practically insoluble in acid
Hazards
MSDS MSDS
EU Index Not listed
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point Non-flammable
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N verify (what isYesY/N?)
Infobox references

Chromium(III) sulfate usually refers to the inorganic compound with the formula Cr2(SO4)3 • 12(H2O). This consists of the hydrated sulfate salt of the metal aquo complex with the formula [Cr(H2O)6]3+, which is responsible for the purple color of this salt. It is widely used in the tanning of leather, with associated environmental damage.[1]

Properties[edit]

Heating chromium(III) sulfate leads to partial dehydration to give a hydrated green salt (CAS#15244-38-9) and eventually the anhydrous derivative (CAS#10101-53-8).

Production[edit]

Basic chromium sulfate is produced from chromate salts by reduction with sulfur dioxide, although other methods exist.[2] The hydrous form may be formed by the reaction of chromium(III) oxide and sulfuric acid.

Cr2O3 + 3 H2SO4 → Cr2(SO4)3 + 3 H2O

References[edit]

  1. ^ http://youtu. be /a0UCeTjhSJI
  2. ^ Gerd Anger, Jost Halstenberg, Klaus Hochgeschwender, Christoph Scherhag, Ulrich Korallus, Herbert Knopf, Peter Schmidt, Manfred Ohlinger (2005), "Chromium Compounds", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a07_067