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.

    532/586 (page 514)
    NaHgPtO, obtained by heating platosodiammonium oxide (p. 515) to 110°, is a greyisli mass, which, when heated to 100° in a close vessel, gives off water, ammonia, and nitrogen, and leaves metallic platinum. The hydroxide, N2HgPt.(HO)2, obtained by decomposing the sulphate ■with baryta-water, is a strong base, soluble in water, having an alkaline reaction, absorbing carbonic acid from the air, and liberating ammonia from its salts (Odling). The sul])lmte, NjHgPtSO^.HgO, and the nitrate, N2HgPt(N03)2, are obtained by boiling the iodide with sulphate and nitrate of silver : they are crystalline, and have a strong acid reaction. The sulphate retains a molecule of crystalUsation-water, which cannot be removed without decomposing the salt. 2. Platososemidiavimonium Compounds. — These com- pounds, isomeric with the preceding, are formed by dii-ect addition /N H CI of ammonia to plattnous salts. The chloride, Pt \^Qf > is ob- taiued by adding ammonia to a cold solution of platinous chloride in hydrochloric acid, filtering after 24 houi-s, and treating the yellowish green residue with boiling water, wliich dissolves the platosemidiam- monium salt, and leaves the green salt of Magnus formed at the same time. The solution on cooling deposits the platososemidiam- monium chloride in small prisms, differhig in form from the chloride above described, and much more soluble in water, requii-ing for solu- tion 387 parts of cold and 26 parts of boUiag water. The other salts of this base are obtained by decomposing the chloride with the corresponding silver salts. The bromide and iodide crystallise in yellow needles; the nitrite in silky needles, which detonate when heated; the nitrate and sulphate form yellowish crystalline crusts. 3. Platosomonodiammonium Compounds, |^ .— The chloroplatinite of this series, 2N3HgPtCl2.PtCl2, formed in small quantity on adding ammonia to a solution of platinous chloride, crystallises in brown square laminae, slightly soluble in cold, more soluble in boUing water. Treated with silver nitrate it is converted into platosomonodiammonium nitrate, and this, when heated with hydrochloric acid, yields the corresponding chloride, NgHgPtCl,, which is very soluble, and crystallises in colourless needles, or nacreous scales. <N H R N^H^R ■ — chloride, i^f JI-i^2^tGl2, one of the earliest discovered of the ammonia- cal platinum c'ompoimds, is obtained by the action of ammonia on the green salt of Magnus, or on the chloride of platosammoniuni. When platinous chloride is boiled with excess of ammonia, till the green precipitate formed in the first instance is redissolved, a solu- tion is obtained, which, when filtered and evaporated, yields the chloride of platosodiammonium in splendid yellow crystals contain- ing one molecule of water, which they give ofi' at 110°. It is soluble in water, and its solution mixed with platinous chloride