Mercury(II) nitrate


Mercury nitrate is a toxic colorless or white soluble crystalline mercury salt of nitric acid. It was used to treat fur to make felt in a process called 'carroting'. The phrase 'mad as a hatter' is associated with psychological illness brought on by excessive exposure to mercury nitrate. The practice continued in the United States until it was banned in December 1941 by the United States Public Health Service. Although this sounds beneficial to health, the ban actually freed mercury nitrate to be used in the manufacture of detonators in the then ongoing war.

Production

Mercury nitrate is made by reacting hot concentrated nitric acid with mercury metal, under these conditions, the nitric acid is an oxidizing agent. Dilute nitric acid would produce mercury nitrate.

Uses

Mercuric nitrate is used in mercuration reactions. In particular, it is used in reactions involving ketones. One of the chemicals which it is most effective with is acetone. This reaction uses mercuric nitrate, mercuric oxide, and calcium sulfate to change acetone, which is CH3CCH3, into CH3CCH2Hg. Acetone is a compound for which most other methods of mercuration prove ineffective. The mercuric nitrate compound works because it is a strong oxidizing agent. In addition, when mercury is dissolved in nitric acid the acid form of mercuric nitrate is formed. The acidic form is capable of inverting molecules of sucrose.

Health information

Mercury nitrate tends to affect the body as Hg2+, which is considered a form of inorganic mercury. Forms of inorganic mercury can be found in various contexts including in skin lightening cream. If the inorganic mercury is ingested it can change the structure of important proteins within the body. If it gets into the soil it can then be absorbed and remain to be taken up by plants. Those suffering from poisoning tend to experience vomiting and diarrhea as their earliest symptoms.

Reactivity

Although mercuric nitrate is not flammable it can speed up flames since it acts as an oxidizer. In addition, it can form explosive compounds when combined with alcohols.