CHLO′′RIDE

(-ĭd). Syn. Chlo′′ruret† ; Chlori′dum , L. A chemical compound of chlorine with a metal or other basic radical, e.g. NaCl, chloride of sodium; C 2 H 5 Cl, chloride of ethyl. Prep. The majority of the metallic chlorides may be made by simply di olving the metal or its carbonate, oxide, or hydrate, in hydrochloric acid (previously diluted with about twice its weight of water), and evaporating and crystallising the solution in the usual manner. Zinc, cadmium, iron, nickel, cobalt, and tin, di olve readily in hydrochloric acid; copper only in strong boiling acid; silver, mercury, and gold, not at all. The insoluble chlorides, as those of silver and mercury, may be readily prepared by precipitating any of their corresponding soluble salts with hydrochloric acid, or a soluble chloride, such as common salt. Anhydrous chlorides are generally prepared by the direct action of chlorine on the bases. Char., Tests, . Most of the metallic chlorides are soluble in water. Many fuse when heated, and volatilise unchanged, but others are completely or partially decomposed at a red heat. All, with the exception of those of the alkali and earth metals, are decomposed at a red heat in a current of hydrogen. They are recognised by the following reactions:—1. Heated with a little peroxide of manganese and sulphuric acid, chlorine is evolved, and easily detected by its colour, smell, and bleaching properties:—2. The soluble chlorides may be readily detected by their solutions, slightly acidulated with nitric acid, giving with a solution of nitrate of silver a white, curdy precipitate (chloride of silver), insoluble in nitric acid, freely soluble in liquor of ammonia, and blackened by the light:—3. The insoluble chlorides may be tested by digesting them in a little liquor of pota a, when a solution of chloride of pota ium will be formed, which may be treated as just directed (2); or the chloride may be di olved in nitric acid, and tested with nitrate of silver as before.