Chromium(III) nitrate
| |
| File:Chromium nitrate crystals.jpg | |
| Names | |
|---|---|
| IUPAC name
Chromium(III) nitrate
| |
| Other names
Nitric acid, chromium(3+) salt
| |
| Identifiers | |
| |
3D model (JSmol)
|
|
| ChemSpider | |
| ECHA InfoCard | 100.033.550 |
PubChem CID
|
|
| RTECS number |
|
| UNII | |
| UN number | 2720 |
CompTox Dashboard (EPA)
|
|
| |
| |
| Properties | |
| Cr(NO3)3 [Cr(H2O)6](NO3)3•3H2O (nonahydrate) | |
| Molar mass | 238.011 g/mol (anhydrous) 400.21 g/mol (nonahydrate) |
| Appearance | Blue-violet crystals (anhydrous) Purple crystals (nonahydrate) |
| Density | 1.85 g/cm3 (nonahydrate) |
| Melting point | 60.06 °C (140.11 °F; 333.21 K) |
| Boiling point | > 100 °C (212 °F) (decomp.) |
| 81 g/100 mL (20 °C) | |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Flash point | Non flammable |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
|
3250 mg/kg (rat, oral, nonahydrate) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Chromium(III) nitrate describes several inorganic compounds consisting of chromium, nitrate and varying amounts of water. Most common is the dark violet hydrated solid, but an anhydrous green form is also known. These compounds are not important commercially but are commonly found in academic laboratories. [citation needed]
Structure
The relatively complicated formula - [Cr(H2O)6](NO3)3•3H2O - highlights the complicated structure of this material. The chromium centers are bound to six water ligands, and the remaining volume of the solid is occupied by three nitrate anions and three molecules of water of crystallization. Such complicated formulas typify hydrated metal salts.
Properties
The anhydrous salt forms green crystals and very soluble in water. At 100 °C it decomposes. The red-violet hydrate is highly soluble in water. Chromium nitrate is used in the production of alkali metal-free catalysts and in pickling.
Preparation
Chromium nitrate can be prepared by dissolving chromium oxide in nitric acid.[1]
References
- ^ Gerd Anger, Jost Halstenberg, Klaus Hochgeschwender, Christoph Scherhag, Ulrich Korallus, Herbert Knopf, Peter Schmidt, Manfred Ohlinger, "Chromium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.