An introduction to the study of chemistry / by Ira Remsen.

  • Ira Remsen
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of chemistry / by Ira Remsen. Source: Wellcome Collection.

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    cipitate, which is mostly insoluble in ammonium sulphide, in nitric acid- [What change will the copper sulphide un- dergo when treated with nitric acid?] Treat a little of the solution with caustic soda, and boil. [What changes take place?] Filter and wash. Mix some of the black precipi- tate with sodium carbonate, and heat in the reducing flame of the blow-pipe. [What evidence do you then get of the presence of copper?] Palladium, ruthenium, and rhodium are three rare ele- ments which closely resemble one another. Palladium forms with hydrogen a compound which in general has the properties of alloys. It has the composi- tion Pd^H, and contains about 600 volumes of hydrogen to 1 volume of palladium. The properties of this substance have led to the view that hydrogen has metallic properties. If by the name metal is meant an element which forms salts with acids, then it may be said that hydrogen bears to other metals a relation similar to that which carbonic acid bears to other acids. Acids are simply salts of hydro- gen, and other metals drive out the hydrogen. Carbon- ates are in the same way decomposed by all other acids. Platinum, osmium, iridium, and gold form a family in which, however, the three first mentioned are the most closely related. Of these three, platinum is the best known. Platinum, Pt (At. Wt. 194.8), occurs almost always ac- companied by iridium, palladium, rhodium, ruthenium, and osmium, in the form of alloys. The ore is found in the Ural Mountains, in California, Australia, and a few other places. It is prepared by treating the ore with strong aqua regia, which dissolves the platinum, together with some iridium. The platinum chloride thus obtained