A Manual of the Chemistry of the Carbon Compounds

THE CARBON COMPOUNDS. 133
pionic acid, a white light amorphous powder, which has the greatest
resemblance to finely divided silica. It dissolves in concentrated
potash solution, and is not precipitated by hydrochloric acid;- but on
boiling the alkaline solution down with sal ammoniac, silicopropiouic
acid is left behind in the insoluble state. It differs from silica, however,
by not being soluble in caustic soda; and moreover on beating
it, it begins to glow, an inflammable gas being evolved. Silicopropionic
acid is the first example of a new class of acids containing SiO.OH
in the place of carboxyl CO.OH.
Silicoheptyl Compounds.*—By the further action of zinc-ethyl and
sodium upon silicopropionic ether, first silieondiethyl ether Si(C2H6)2
(OC,H6)2 is formed, a liquid boiling at 155-8", which in appearance
and smell is very similar to silicic ether. On very prolonged treatment
with sodium and zinc-ethyl, silicokcptyl ether Si^HJgOCjHj,
a liquid boiling at 163°, is produced. On heating with acetyl chloride
to 180" it yields ethyl acetate and silicmtriethyl elihride, or sUicoheplyl
chloride Si(CJI6)3Cl, a liquid having a pungent and camphorlike
smell, and boiling at 143*5°. It is readily decomposed by
aqueous ammonia, with the formation of silioon trkthyUiydrooMe or
tertiary silieoheptyl alcohol Si(C2H6)sOH. This body may be regarded
as triethyl carbinol, in which one atom of carbpu is replaced by
silicon, and may therefore be called triethyl silicol, It is a colourless
liquid, smelling like camphor, and boiling at 154°.
By the action of fuming sulphuric acid on triethyl silicol it is
oxidized with the formation of silicopropionic acid and ethene :—
2SOS = Si(C2H6)O.OH + 2C2H4 + 2SO8 + H.0
When silicoheptyl ether is heated with hydriodic aoid it yields
Si("C H ) 1
ethyl iodide and silieoheptyl oxide gj/Q^jj) f 0, a colourless liquid,
boiling at 231°.
'
Sodium aots violently on a solution of triethyl silicol in pure ether,
the compound Si(C?H6)3ONa being formed, which ia a white powder.
By passing dry carbon dioxide into its ethereal solution, a white
precipitate is produced of sodium sUicolieptyl-carbonate SifCgH^O.
CO.ONa. It is veiy deliquescent, and is resolved by water into triethyl
silicol and sodium oarbonate. When heated to redness it is
resolved into silicoheptyl oxide and sodium carbonate, being the first
silicon-containing body that leaves carbonate instead of silicate when
heated.
ETHANE AND ITS SUBSTITUTION-PRODUCTS.
Ethane C,HS is a colourless gas, which, as we have just seen, may
be obtained by different reactions. Pure ethane is formed by passing
a galvanic current through a concentrated solution of potassium
acetate; the gas must be washed with caustic potash and concen-
l