Chemical Dictionary states that the chemical formula for chromium (III) nitrate nonahydrate is Cr(NO3)3.9H2O. The formula can also be expressed as CrH18N3O18. Chromium nitrate is the chromium salt of nitric acid. The nitrate exists as a nonahydrate.
Anhydrous salt produces green-black monoclinic crystals. These crystals are extremely soluble in water. With a melting point at 60 degrees Celsius, they decompose at 100 degrees Celsius. The result is a red- or violet-colored hydrate.
The highly complicated structure of chromium nitrate nonahydrate has a formula mass of 400.14 g/mol and a density of 1.807 g/cm3. It is used in pickling and to produce alkali-metal-free catalysts.