A Manual of the Chemistry of the Carbon Compounds

142 THE CHEMISTRY OF
If silicon tetrachloride is digested with a mixture of acetic acid
and acetic anhydride, aeetyl silicon oxide or silico-acetic anhydride
SitCHO^ is formed :—
O + SiCl, e (Cflfijfli + 4HC1
It forms beautifully white crystals, which if thrown into water
decompose with a hissing noise, acetic acid and silicic acid being
formed.
If acetic anhydride is heated with ethyl silicate a reaction sets in
by which ethyl acetate and triethyl-acetyl silicate are formed :—
OC2H6
Etbyl-acetyl silicate is a liquid, which has a faint smell of acetic
acid, and boils at about 190°.
Aeetyl Peroxide QVQ [ 02.—To obtain this compound, pure batittm
peroxide is added to a solution of acetic anhydride in ether; the liquid
is separated from the barium acetate by filtration, and evaporated at
a low temperature. The peroxide is left behind as a thick liquid,
which on heating explodes with great violence. It has a burning taste,
and is as powerful an oxidizing agent as hydrogen peroxide; it
decolorizes indigo solution, sets iodine free from potassium iodide, and
converts potassium ferrocyanide into ferricyanide, This substance is
formed according to the equation:—
Thiacetic AM *^W r S is obtained by distilling acetic acid with
phosphorus pentasulphide t—
O + P2S6 = 5 C * H »°}s + P806
Freshly prepared it is a colourless liquid, but after some time it
becomes yellow; it boils at 93°, and smells like hydrogen sulphide and
acetic acid. It is soluble in water, and forms crystalline salts, the
most characteristic of which is lead tkiacetate, which crystallizes from
water in white needles which cannot ba kept, as they soon decompose,
leaving lead sulphide behind.
When phosphorus pentasulphide acts upon acetic anhydride, aeetyl
sulphide or thiacetic anhydride Q*IJ 8 O J S is formed, a colourless liquid
3 8 J