Image from page 117 of "Practical methods of organic chemistry" (1901) (14584996629)

Identifier: practicalmethods00gatt
Title: Practical methods of organic chemistry
Year: 1901 (1900s)
Authors: Gattemann, Ludwig. [from old catalog]
Subjects:
Publisher: [n.p.]
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

Text Appearing Before Image:
s section) with sodium bicarbonate. In order to absorb thewater generated from this on heating, a small sulphuric acid washbottle is interposed between the two tubes. The layer of bicar-bonate is heated with a single Bunsen burner, beginning at thefused end. In order to protect the bicarbonate tube from thedirect flame, it is surrounded by a cylinder of coarse iron gauze(Fig. 5 7). The bicarbonate may be replaced by a Kipp generator. Further, the mixing of the substance with the fine copper oxidemay be done in the tube. Instead of the absorption apparatusof Schiff, described above, a graduated tube from which the vol-ume of the gas may be read directly may be used, thus obviatingthe necessity of transferring it to a eudiometer. This modifica-tion carries with it, however, the disadvantage that the tension of H 98 GENERAL PART caustic potash is not exactly known, and therefore a somewhatarbitrary correction must be applied. But as mentioned thesemodifications do not differ essentially.
Text Appearing After Image:
Fig. 57. QUANTITATIVE DETERMINATION OF CARBON AND HYDROGENLIEBIGS METHOD The essential part of the method consists in completely burningwith copper oxide a weighed amount of the substance, and thenweighing the combustion products, carbon dioxide and water. The requisites for analysis are : 1. A hard glass tube open at both ends; outside diameter 12- 15 mm. It should be about 10 cm. longer than the furnace. 2. Four hundred grammes of coarse and 50 grammes of fine copper oxide, preserved in bottles closed with tin-foil-covered corks as in the nitrogen determination. But thecopper oxide used for the latter purpose and that for thecarbon and hydrogen determinations are always kept inseparate bottles. 3. A U-shaped and a straight calcium chloride tube. 4. A caustic potash apparatus. The Geissler form is the most convenient. 5. A drying apparatus for air or oxygen. 6. Two one-hole rubber stoppers fitting the ends of the com- bustion tube. 7. A glass tube provided with a cock. 8. Two copper