The chloride ion is formed when the element chlorine picks up one electron to form an anion (negatively-charged ion) Cl-. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. An example is table salt, which is sodium chloride with the chemical formula NaCl. In water, it dissolves into Na+ and Cl- ions.
The word chloride can also refer to a chemical compound in which one or more chlorine atoms are covalently bonded in the molecule. This means that chlorides can be either inorganic or organic compounds. The simplest example of an inorganic covalently-bonded chloride is hydrogen chloride, HCl.
Sodium chlorate (NaClO3) is an oxidizing agent. It is mostly used to produce chlorine dioxide for bleaching paper pulp, but is also used as a herbicide and to prepare other chlorates. Production in the United States is about 441000 tons per year.
When pure, it is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes above 250 °C to release oxygen and leave sodium chloride. It is synthesised from the electrolysis of hot sodium chloride solution in a mixed electrode tank. It can also be synthesised by passing chlorine gas to a hot sodium hydroxide solution. It is then purified by crystallization.
