Copy 1

Outlines of the course of qualitative analysis followed in the Giessen laboratory / By Henry Will ; With a preface by Baron Liebig.

  • Heinrich Will
Date:
1846
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of the course of qualitative analysis followed in the Giessen laboratory / By Henry Will ; With a preface by Baron Liebig. Source: Wellcome Collection.

    48/152 page 32
    chloride of sodium to redness, and passing a stream of chlorine over it. | The solutions of sesquioxide of rhodium are generally of a beautiful rose-red colour; the solution obtained by fusion with bisulphate of potassa is yellow, but becomes red on digestion with hydrochloric acid. Hydrosulphuric acid throws down from the salts of rhodium a brown sesquisulphide, R, S8,. This precipitate appears only after a short time, and the supernatant liquid remains red for some time. Sulphide of ammonium acts like hydrosulphuric acid. Sul- phide of rhodium is insoluble in an excess of sulphide of ammonium. e Ammonia and carbonate of ammonia throw down after some time a yellow double compound of sesquioxide of rhodium and ammonia, which is soluble in hydrochloric acid. The fixed caustic alkahes and their carbonates give after long boiling a yellowish-brown precipitate. The red colour of the solutions of this sesquioxide (which after treatment with hydrosulphuric acid is still visible) and its in- solubility in acids distinguish rhodium from all other metals. [k. OXIDES OF OSMIUM.] Os O, Os O,. Metallic osmium, especially in the state of fine powder, when ignited in atmospheric air or oxygen, is converted into osmic acid, Os O,, the vapour of which resembles chlorine and iodine, but is even more insupportable. The inferior oxides, when ignited in contact with air, are also converted into osmic acid. Osmium dissolves in nitric and nitro-hydrochloric acid, osmic acid volatilising, which may be easily recognised by its suffocat- ing smell. Solutions of the salts of oxide of osmium and of osmic acid in water, acids and alkalies, are precipitated by hydrosulphuric acid as a brownish-black sulphide, which is insoluble in sulphide of ammonium. Osmic acid in solution is reduced to the metallic state by most
    digitised image 1
    digitised image 2
    digitised image 3