Volume 1

Fownes' manual of chemistry : theoretical and practical / [George Fownes].

  • Fownes, George, 1815-1849.
Date:
1877
Catalogue details

Licence: Public Domain Mark

Credit: Fownes' manual of chemistry : theoretical and practical / [George Fownes]. Source: Wellcome Collection.

    547/586 (page 529)
    111^,83.. Wlien hydrogen sulphide is passed for a long lime into a solution of the trichloride, ruthenium disulphide, EuSg, is formed, as a brown-yellow precipitate, becoming dark-brown by calcination. Ammoniacal Ruthenium Compounds.—Tctravimonio-hvporu- tJienious Chloride, 4NH3.RuCl2.3H2O or Ru[NH2(NH^)Cl]3.3H20, is formed by boiling the solution of ammonium chlororntheniate (RuCl^.aNH^Cl) -with ammonia. It forms golden-yellow oblique rhombic crystals, very soluble in water, insoluble in alcohol. Treated with silver oxide, it yields the corresponding oxide, 4NH3RUO, which, however, is decomposed by evaporation of its solution, giving off half its ammonia, and leaving the compound, 2NH3.RUO. The carbonate, nitrate, and sulphate, obtained by treating this last-mentioned oxide with the corresponding silver salts, form yellow crystals. The compoimds of ruthenium may readily be distinguished from those of the other platinum-metals, by fusing a few milligrams of the substance in a platinum spoon, with a large excess of nitre, lea\dng it to cool when it ceases to froth, and dissolving the cooled niass in a little distilled water. An orange-yellow solution of potas- sium rutheniate is thus formed, which on addition of a di-op or two of nitric acid, yields a bulky, black preciiaitate; and on adding hydrochloric acid to the liquid, with the precipitate still in it, and heating it in a porcelain crucible, the oxide dissolves, forming a solution which has a fine orange-yellow colour when concentrated, and when treated with hydrogen sidphide, till it becomes nearly black, yields a filtrate of a splendid sky-blue colour. Characteristic reactions are also obtained with potassium sidphocyanate, which colours the liquid deep red, changing to violet on heating, and with had acetate, which forms a pm-ple-red precipitate. OSMIUM. Atomic weight, 199-2. Symbol, 0.s. The separation of this metal from iridium, ruthenium, and the other inetals with which it is associated in native osmiridium, and in platmum residues, depends chiefly on its ready oxidation with nitric or nitromuriatic acid, or by ignition in air or oxygen, and the volatility of the oxide thus produced. To prepare metallic osmium, the solution obtained by condensing the vapour of osnnura tetroxide in potash (p. 527) is mixed with exce.ss of hydrochloric acid, and digested with mercury in a well- closed bottle at 40^. The osmium is then reduced by the mercury and an amalgam is formed, which, when distilled in a stream of FOWNES.—VOL I. 9t