Introduction to the study of inorganic chemistry / by William Allen Miller.

  • Miller, William Allen, 1817-1870.
Date:
1871
Catalogue details

Licence: Public Domain Mark

Credit: Introduction to the study of inorganic chemistry / by William Allen Miller. Source: Wellcome Collection.

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    it to redness in a clay crucible for a considerable time. Kitrogen and oxygen are exj^elled, and cupric oxide is left as a black powder. It is .soluble in acids, and furnishes the blue and green salts of the metal. A solution of any one of these salts, such as the sulphate, when decomposed by ].)olash, gis'es a pale blue h}’drated cupric oxide, which, when boiled in water, becomes black and anhydrou.s. Ammonia gives a similar ])reci|)itate, which is retlissolved by an excess of the alkali, furnishing an intensely blue liquid, charac- teristic of copper. The sulphate, or blue vitriol (CuSO^, 51^20), is its most imi)ortant salt. It is easily obtained on the large scale by boiling metallic copper with oil of vitriol diluted with half its bulk of water. It crystallises in beautiful blue i)risnis, which, when heated, lose water, and crumble down to a white |)Owder. Cupric chloride (CuCb, 211,0) maybe obtained by dis- solving the carbonate or the oxide in h^-drochloric acid, and evaj'orating. Its crystals are green, and form a green solu- tion, which becomes blue on dilution. When heated, it loses water, and then half its chlorine, cupreous chloride (CuCl) being formed. Cui)reous chloride is also formed when a solution of laipric chloride in h)'drochloric acid is digested on copper in closed r'essels ; it crystallises gradually in transparent tetrahedra, insoluble in water, but soluble in e.Ncess of hydrochloric acid. Cupreous sulphide (Cu,S) is occasional!)' found native, as is also the c/i'/’/'/V (CuS), which is ])recipitated as a brownish-black hydrate when a solution of a cupric salt is ex])0sed to the action of sulphuretted hydrogen. Tests for Copper. — In addition to the characteristic blue liciuid formed in solutions of cu])ric salts by the addition ot excess of ammonia, they are known by their forming a brown l)recipitate with potassic ferrocyanide, and by the de])0Sit of metallic cojiper which is jiroduccd on a polished i)late oi iron, if plunged into a feebly acid solution of a cujwic salt.