A Manual of the Chemistry of the Carbon Compounds

320 THE GHMMJSTSY OF
consists in the decomposition of a salt of diazobenzene with hydriodic
acid. Substitution-products of beuzene are also produced by
treating silver benzoate with iodine chloride -.—
C6H6.CO2Ag + IC1 = C6H5I + AgCl + CO,
Monofiuobenzene CSH6F, is produced by distilling fluobenzoic acid
with quicklime. It is a scaly, crystalline mass, melting at 40°, and
boiling at 180°. Its odour resembles that of benzene,
Mtrdbenzem C6H6NO8.—Benzene dissolves in concentrated nitric
acid with the evolution of heat; on the addition of water, nitrobenzene
is precipitated as a heavy oily liquid:—
CA + NO^OH - C6H8N02 + H2O
Nitrobenzene has generally a brown colour, but when quite pure it
is a pale yellow, strongly refractive liquid, boiling at 220°. It has a
burning sweet taste, and a smell resembling that of oil of bitter
almonds, and of cinnamon.
Mnitrobmzme C6H.(FOj)2 is formed by boiling nitrobenzene with
strong nitric acid, or by acting upon benzene with a mixture of concentrated
sulphuric and nitric acids. It crystallizes from nitric acid
or from alcohol in long, glistening, colourless needles, melting at 86°.
"When mono- or dinitrobenzene, or other nitro-compounds are
heated with potash, they are decomposed, yielding potassium cyanide,
and other products which have not been examined!
By the action of strong nitric acid upon the substitution-products
of benzene, already described, nitro-compounds of the latter are
obtained.
Benzenesulpkmic Add C8H?.SOa.OH.—When benzene is shaken
with concentrated sulphuric acid, it is dissolved :—
SO8 j ° | =; C6H6.SOyOH + H8O
On neutralizing the diluted solution with carbonate of barium or
lead, the excess of sulphuric acid is removed, and the solution contains
the benzenesulphonates of these metals. To obtain the free
aoid, the salts are decomposed either by sulphuric acid or hydrogen
sulphide, and the filtered solution is evaporated, Benzeuesulphouio
acid forms small colourless deliquescent plates.
fienzcncsulphonic Chloride C6H5.SOaCl is obtained bythe action of
phosphorus puntachloride upon sodium benzenesulphouate; it is an
oily liquid boiling at 246°, which ia decomposed by boiling water.
By the action of ammonia it is converted into Senzenesulplwnamidc
ORH..SO a colourless crystalline solid,
f SO OH
Bemmedimlplwnia Add CeH4-J gQ^nH ^ produced by heating
the monosulphonic acid with fuming sulphuric acid. It forms ,i
crystalline deliquescent mass. Tde barium-salt ia very soluble in
water, but the lead-salt less so.