Theoretical organic chemistry / by Julius B. Cohen.

  • Julius B. Cohen
Date:
1902
Catalogue details

Licence: Public Domain Mark

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

    39/604 (page 19)
    12 x a x ioo 44 x zv 2 X b X IOO a--— 18 x ® = per cent, of carbon, per cent, of hydrogen. Example /.—0*1830 gram of substance gave o'6ii8 gram of C02 and o'1315 gram of H20. 12 x '6118 x 100 r . „ = 92* 3 per cent, of carbon. 44 x '1830 7 J r 2 x *1315 x IOO r 1 1 „—0 J-— 7-9 per cent, of hydrogen. 18 x '1830 As the two quantities added together make, within the limits of experimental error, 100 per cent., no oxygen is present. Example II—0*1510 gram of substance gave o'io55 gram of C02 and o'o68 gram of H20. 12 x ’1055 x IOO 44 x '1510 2 x -o68 x 100 18 x '1510 19*05 per cent, of carbon. •00 per cent, of hydrogen. Here the difference between 100 and the aggregate per¬ centages of carbon and hydrogen is 75*95, and must be due to the presence of oxygen, seeing that no other elements were found. Volatile liquids are inclosed in small bulbs (Fig. 14), which are carefully weighed. The liquid is then introduced, and the neck sealed. Before placing the bulb in the tube, the neck is scratched with a file and opened. If the organic substance contains nitrogen, Fig. 14. the latter may be liberated in the form of one or other of its oxides. These would be absorbed in the potash apparatus, and cause an error in the amount of carbon. A spiral of metallic copper is therefore brought into the front end of the combustion tube, which, when red-hot, reduces the oxides of nitrogen. The free nitrogen then passes through unabsorbed. When halogens, or sulphur are present in the organic compound, they are also liable to be absorbed either in the free state, or in combination with oxygen in the potash1 C 2