chlorideschemical

Chlorides are a broad class of chemical compounds that contain the chloride ion (Cl−) or chlorine bound in a −1 oxidation state. They include many inorganic chlorides such as sodium chloride (NaCl) and hydrogen chloride (HCl), as well as organochlorine compounds in which chlorine is bonded to carbon or other elements. In inorganic chlorides, the bonding is predominantly ionic, whereas many organochlorides feature covalent bonds.

Major categories include alkali and alkaline earth metal chlorides (for example NaCl, KCl, CaCl2), transition metal chlorides (such as FeCl3, NiCl2), and hydrogen chloride. Organochlorides cover solvents, refrigerants, pesticides, and polymers such as vinyl chloride (VCM) used to synthesize polyvinyl chloride (PVC).

Chlorides occur naturally in minerals such as halite (rock salt) and are produced industrially by various routes. NaCl is obtained from seawater or rock salt and is often produced by mining or evaporation. Industrial processes of brine electrolysis produce chlorine gas and caustic soda, with NaCl as the feedstock. Hydrogen chloride is produced by burning chlorine in hydrogen or by processing hydrochloric acid. Many chlorides are prepared by direct reaction of a metal with chlorine, or by reacting an oxide or hydroxide with hydrochloric acid.

Chlorides have diverse applications. Sodium chloride is used in food seasoning and preservation; calcium chloride is used for de-icing and as a drying agent. Vinyl chloride monomer is polymerized to PVC. Metal chlorides such as ferric chloride are used as catalysts and etchants in various chemical and electronic applications.

Exposure to chlorides varies by compound. Some, such as hydrogen chloride and chlorine gas, are highly corrosive and toxic. Organ chlorides range from benign salts to persistent environmental pollutants; handling requires appropriate safety measures.