Mercurous chloride

Mercurous Chloride is a chemical compound with the formula Hg2Cl2. Also known as calomel or mercurous(I) chloride, it is a common compound of mercury. It is a white or yellowish-white, odorless, heavy, earthy powder that is insoluble in alcohol but slightly soluble in water. It is used in medicine, in particular in traditional systems of medicine like Ayurveda and Unani.

History

Mercurous chloride was used in the treatment of diseases such as syphilis before the advent of antibiotics. It was also used as a diuretic, and as a topical disinfectant and astringent.

Preparation

Mercurous chloride is prepared by combination of mercury and chlorine. The reaction is exothermic and the product, mercurous chloride, is obtained as a white precipitate.

Properties

Mercurous chloride is a white crystalline solid. It is sparingly soluble in water, but soluble in solutions of chlorides. It is a coordination compound, with each mercury atom surrounded by two chloride ions.

Uses

Mercurous chloride is used in medicine, in particular in traditional systems of medicine like Ayurveda and Unani. It is also used in the manufacture of batteries, and as a standard in electrochemical measurements.

Safety

Mercurous chloride is toxic by ingestion, inhalation and skin contact. It is a potential human carcinogen and is particularly dangerous to the kidneys.

See also

• Mercury (element)
• Mercuric chloride
• Mercury poisoning