Licence: Public Domain Mark
Credit: Qualitative chemical analysis / by C. Remigius Fresenius. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![For the sake of greater clearness and ^^Pli^J^; J^S' «f crrnxm into two classes, and clistmguisn, _ oxjdes hydrochloric acid, viz., oxide of *r~Tof ;^?c^ilble by hydrochloric acid vi., iS'SS^Ji^a-it'^o^Lpd^ ^^^s it efcting its perfect separation from the oxrdes of the second division. Special Reactions of the more common Oxides of tlie fifth group. First Division : Oxides which are precipitated by Hydrochloric Acid. § 115. a. Oxide of Silver, AgO [Ag.O]. 1. Metallic silver is white, very lustrous, moderately ha^^^^^ malleable rather difficultly fusible. It is not oxidized by fusion m the Til Nitkc^^^^^ dissolves sHver readHy ; the metal is insoluble m ddute sidphuric acid and in hydrochloric acid. ., • + u„„^fVo-r 2 Oxide of silver is a grayish-brown powder ; it is not altogether insoluble in water, and dissolves readUy in dilute nitric acid^ It forms no hydrate. Both the oxide and the peroxide of silver, AgO, [Ag.O.I, are decomposed by heat into metallic silver and oxygen 3 The^alts of oxide of silver are non-volatde and cota- less • but many of them become black on exposure to light. iJie soluble neutra salts do not alter vegetable colours, and are decomposed at ^^Sulphuretted hydrogen and sulphide of ammonium yield a precipitateof black sulphide of silver, AgS [Ag,S], which is insoluble in dilute acids, alkalies, alkahne sulphides, but soluble m cyamde of potassium. Boihng nitric acid decomposes and dissolves this precipitate readily, with separation of sulphur. ■ j.r. c ^ 5. Potassa and soda precipitate oxide of silver m the form of a grayish-brown powder, which is insoluble in an excess of the precipi- tants, but dissolves readily in ammonia. i 6 Ammonia, if added in very small quantity to neutral solutions, throws down the oxide as a brown precipitate, which readily redissolves in an excess of ammonia. Acid solutions are not precipitated. 7 Hydrochloric acid and soluble metallic chlorides produce a white curdy precipitate of chloride of silver, AgCl [AgCl] It the solutions are very dilute, however, there is merely a bluish-wlute opales- cence at first; but on long standing in a warm place the cUoride of silver collects at the bottom of the vessel. By the action of light, the white chloride of silver loses chlorine, first acquiring a violet tint, and ulti- mately turning black; it is insoluble in nitric acid, but dissolves readily in ammonia as ammonio-chloride of silver, from which double compound](https://iiif.wellcomecollection.org/image/b21966953_0163.jp2/full/800%2C/0/default.jpg)
