Theoretical organic chemistry / by Julius B. Cohen.

  • Cohen, Julius B. (Julius Berend), 1859-1935.
Date:
1902
Catalogue details

Licence: Public Domain Mark

Credit: Theoretical organic chemistry / by Julius B. Cohen. Source: Wellcome Collection.

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    ANALYSIS OF ORGANIC COMPOUNDS Qualitative Tests Having prepared the substance in a pure state, the next step is to determine its constituent elements. Carbon and Hydrogen.—Compounds of carbon are frequently inflammable, and when heated on platinum foil take fire or char. A safer test for carbon is to heat the substance with some easily reducible metallic oxide, the oxygen of which forms carbon dioxide with the carbon present, which is detected by passing the gas through lime-water. Hydrogen, if present, is at the same time converted into water, which condenses in drops on the cold part of the apparatus. Expt. 2.—Take a piece of soft glass tube about 13 cm. long, and fuse it together at one end. Heat a gram or two of fine copper oxide in a porcelain crucible for a few minutes to drive off the mois¬ ture, and let it cool in a Fig. 8.—Apparatus for detecting carbon, desiccator. Mix it with about one-tenth of its bulk of powdered sugar in a mortar. Pour the mixture into the tube, and draw out the open end, bending it at the same time into the form shown in Fig. 8. Suspend it by a copper wire to the ring of a retort stand, and let the open end dip into lime