A Manual of the Chemistry of the Carbon Compounds

THIS CAKBON UOMPOUNtm. fl)
EMPIRICAL, RATIONAL, AND CONSTITUTIONAL
EOWLVL2E,
The simplest mode of expressing the composition of a body is to
write side by side the symbols and numbers of the constituent
atoms: —
C«H. . . Ethane. CJHJCIOJ Chloracetic Acid.
8 6 y
Ethyl Chloride. C4H8O4 . Ethyl Acetate.
C2HBO . . Ethyl Alcohol.
C.H.N . . Ethylarnine. CgH^C
C.BLO. . Diethvl Ether. C2H0O,
OJLO. . Acetic Acid. Cfifi.
CHOUl . Acetyl Chloride. OftO
Ethene.
Ethene Chloride.
Ethene Alcohol.
Glycollic Acid.
Oxalic Add.
Such formula are called empirical formula: But as the number
of carbon compounds is so very large, and as there exists amongst them
a considerable number of Isomrides, Le. compounds having the same
percentage composition bnt possessing very different physical and
chemical properties, it has been found necessary to use othera as well
as these empirical forniulre, for the purpose of giving an idea of the
chemioal character of the body, or to express the relation it bears to other
compounds. We call such formulse rational formula. Thus, all the
ethyl compounds contain the monad radical C4H5, and we can represent
those contained in the table given above as follows:—
j | 10 Ethyl Alcohol. rf iN Ethylamine.
These formulas express that, when we replace, for instance, in ethanl)
one atom of hydrogen by one of chlorine, we obtain ethyl chloride ;
and that, by substituting the chloride by monad hydroxyl or the
monad group NHL ethyl alcohol or ethylamine are formed. The
formula of alcohol lurtber indicates that its constitution is analogous to
water, and that it may be regarded as water in which hydrogen has
been replaced by ethyL From the rational formula of ethylamine it
follows that it has a constitution similar to that of ammonia. By
replacing the hydrogen in the hydroxyl of alcohol by ethyl we obtain
diethvl ether A/ !• 0, which may be regarded as water in which
ethyl occupies the place of hydrogjeo.
By acting on alcohol with oxidizing agents, two atoms of hydrogen
are taken otit and their places are occupied by oue atom of oxygen,