Chromium(III) nitrate, with the chemical formula Cr(NO3)3, is an inorganic compound containing chromium in its +3 oxidation state. It is a dark violet or purple crystalline solid and is a common chromium salt.

Preparation of Chromium(III) Nitrate: Chromium(III) nitrate can be prepared by dissolving chromium(III) oxide (Cr2O3) in nitric acid (HNO3):

Cr2O3 + 6 HNO3 → 2 Cr(NO3)3 + 3 H2O

Another method involves the reaction of chromium metal or chromium hydroxide (Cr(OH)3) with dilute nitric acid:

2 Cr + 6 HNO3 → 2 Cr(NO3)3 + 3 H2O

Properties and Uses of Chromium(III) Nitrate:

• Appearance: Chromium(III) nitrate is a dark violet or purple crystalline solid.
• Solubility: It is soluble in water, and the resulting solution can be acidic due to the hydrolysis of the nitrate ions.
• Catalyst: Chromium(III) nitrate can act as a Lewis acid catalyst in certain organic reactions.
• Oxidizing Agent: It exhibits some oxidizing properties, although it is not as strong an oxidizing agent as some other chromium compounds.
• Dyeing and Pigments: Some chromium(III) compounds, including chromium(III) nitrate, are used as mordants for dyeing textiles and as pigments in ceramics and glass.

Safety Considerations: Chromium(III) nitrate is generally considered to be of low toxicity. However, like other chromium compounds, it should be handled with care, and safety precautions should be followed. Avoid inhaling the dust and prevent skin contact by wearing appropriate personal protective equipment (PPE).

As with all chemicals, it is essential to consult the Material Safety Data Sheet (MSDS) and follow strict safety protocols when working with chromium(III) nitrate.