A Manual of the Chemistry of the Carbon Compounds

TEE CARBON COMPOUNDS. 161
in water, and does not crystallize, but dries up into an amorphous
gam-like mass.
Secondary Propyl Alcohol, or Dimethyl Carbinol QJJ 3 >-CH. OH, also
called isopropyl alcohol, may be obtained from the primary alcohol by
heating it with an excess of concentrated sulphuric acid, by which it
is decomposed into water and propene C«He. This gas is absorbed
by shaking it with cold sulphuric acid, and isopropyl sulphuric acid is
formed, thus:—
CHS
H2
which on boiling with water is decomposed into sulphuric acid and
the secondary alcohol. To obtain it in larger quantity, it is best
to act on its iodide with silver salts, and to decompose the ethets
thus formed with caustic potash.
Dimethyl carbinol is a colourless liquid with a vinous smell, boiling
at 84°. It mixes with water in all proportions, and forms a hydrate
2C8H^O+H2O, which boils without decomposition at 78°, and has
thus the same composition and boiling-point as ethyl alcohol. On
heating it with the hydracids of the chlorine elements, the secondary
chloride, bromide, and iodide are obtained.
Isopropyl Iodide QJJ 3 > CHI is also formed by the direct combination
of propene and hydriodic acid, but is best prepared by heating
glycerin CjHgOj, a triad alcohol, with an excess of fuming hydriodic
acid:—
CHjOH 0H3
CHOH + SHI » CHI -t- BB.fi + 2Ia
CH3OH Clf3
It is a heavy colourless liquid, boiling at 89°. When it is heated
with water and silver oxide, isopropyl alcohol and isopropyl ether
(CH YCH I < " > ~~ a *te nt mobile liquid with an ethereal 8mell and boiling
at 60°—are formed.
On bringing the iodide together witli water and hydrochloric acid,
propane CgH8 is evolved, a gas bunting with a luminous flame.
When acted upon by chlorine in diffused daylight, it yields, besides
other substitution-products, primaTy propyl chloride. This transformation
from the secondary to primary propyl compounds takes
place according to the following equations:—