Hydrochloric acid

Hydrochloric acid is a dangerous chemical that has many important industrial uses. The acid is a colorless liquid with an irritating odor. It fumes when exposed to air. It is highly corrosive and can cause serious burns.

Hydrochloric acid is also called muriatic acid. Its chemical formula is HCl. The acid is made by dissolving hydrogen chloride gas in water. The hydrogen chloride gas itself is prepared by burning hydrogen and chlorine gases together or by treating common table salt, sodium chloride, with sulfuric acid. Hydrochloric acid is most commonly sold as a 30 percent solution, called concentrated hydrochloric acid. Neutralization of the acid forms salts called chlorides.

Industry uses hydrochloric acid in preparing many chemical compounds. The acid is also used in metallurgy and food processing. In most people, the stomach secretes small amounts of hydrochloric acid, which aids in digestion. However, excess production of the acid by the stomach contributes to the formation of stomach ulcers.