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.

    47/604 (page 27)
    CHAPTER III EMPIRICAL AND MOLECULAR FORMULAS Empirical Formula.—From the results of an analysis it is possible to calculate the relative number of atoms of the different elements present in an organic compound. This is done by dividing the percentage weights by the atomic weights of the elements. If we take the first example of an analysis of carbon and hydrogen (p. 19), and divide the numbers repre¬ senting the per cent, of carbon and hydrogen by the respective atomic weights of these elements, we .obtain approximately the same quotient— Q2' 2 c H 12 T9 1 - 77. - 7-9. The ratio of the number of carbon to hydrogen atoms is 1 : 1, and the substance may be represented by the formula CH. This is known as the empirical formula. The real formula of the substance is without doubt some multiple of the empirical formula ; but an analysis can give no further information upon this point. Let us now take the numbers in the second example, and divide by the atomic weights. We obtain the following quotients— 19'° 5 12 C ~ • = r59-