A Manual of the Chemistry of the Carbon Compounds

TBE CARBON COMPOVNVS. 145
^ ' JT|O. Nascent hydrogen easily reduces monochloracetic
acid to acetic acid, and phosphorus trichloride converts it into mono-
CH CLCO)
chloraeetyl chloride 2 ci I' a com P oun( ^ which is also formed
by the action of chlorine upon acetyl chloride. It is a colourless
liquid, possessing a pungent and suffocatiug smell, and boiling
at 105". Water decomposes it into ohloracetic acid and hydrochloric
acid. With ethyl alcohol it yields ethyl monochloracetate
CHsCJj^ I o, a liquid boiling at 143°-5, and possessing a pleasant
smell. It is also formed by passing hydrochloric acid gas into an
alcoholic solution of monochloracetic acid. By acting on this ether
with ammonia, monoehhraeetamdde ^ ' g !• N is formed, which
is soluble in water and crystallizes in shining scales.
Didiloracetic AM
v g>Ois obtained by the further action
of chloiiue on monochloracetic acid; it forms colourless crystals,
and boils at 195°. Potassium dichloracetate CB:C1 2- C ^jo crystal-
lizes from alcohol in large silky plates.
Tnchloracelic Acid TT f O>—^Ms ^ii can ^* obtained in
different ways. It is formed when an excess of chlorine acts on
acetic acid in the sunlight, but the most convenient method to obtain
it in large quantities is to oxidize chloral hydrate (see below) with
fuming nitric acid. It is also produced by heating perchlorethyl
oxide, whioh at 300° is resolved into hexaMmtfiane C,Cla and tri-
acetyl chloride ^a-^ I. Xhe latter, in contact with water, yields
hydrochloric acid and trichloracetic acid.
Trichloracetic acid-crystallizes in colourless rhombohedrons and
boils at 195°; it is very caustic, producing blisters on the skin, and
it is very readily soluble in water. The trichloracetates are well defined
salts; lead trichloracetate Pb^CgC^O^a+HjO is readily soluble in water
and forms large rhombic prisms; copper trichloracelate C^CjCljO^
+ 6H2O can be easily obtained in large crystals resembling copper
sulphate. On distilling the ammonium salt with phosphorus pentoxide,
trickloracetonitrUe CjClgN is formed, a colourless liquid boiling
at 81°, which, by means of caustic potash, can be reconverted into
trichloracetic acid. On heating this acid with alkalis it splits up
into chloroform and carbon dioxide:—
C
I - CClaH + CO,
CO.OH