any one of a group of compounds of chlorine with all elements possessing lower electronegativity, that is, with all metals and nonmetals except oxygen and fluorine. (The chlorides of nitrogen constitute another exception; they are named thus, although the electronegativity of nitrogen is greater than that of chorine.)
Metal chlorides (or salts of hydrochloric acid) are solids, most of which melt or vaporize without decomposition. Most are readily soluble in water except AgCl, CuCl, HgCl2, TlCl, and PbCl2, which are poorly soluble. The chlorides of alkali and alkaline-earth metals are neutral. Solutions of chlorides of other metals are acidic as a result of hydrolysis; for example, AlCl3 + 3H2O = Al(OH)3 + 3HCl.
Chlorides of nonmetals may be gases (HCl), liquids (PCl3), or solids (PCl5). Such compounds are hydrolyzed by water; for example, PCl5 + 4H2O = H3PO4 + 5HCl.
Sodium chloride, potassium chloride, magnesium chloride, and calcium chloride are common in nature (see).
For information on the properties, production, and uses of chlorides, seePOTASSIUM CHLORIDE; SODIUM CHLORIDE; MAGNESIUM CHLORIDE; CALCIUM CHLORIDE; and TITANIUM HALIDE.