A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...

THE CHEMISTRY OF ANTIMONY. 33
Some of the important salts of these acids are:—
(SbO3K).,5H2O. SbO3LL
Sb2O7K4. Sbo07(^H4)Ho.6H.O.
Sb2O7K2H2.6H.2O. (NH4)Sb03. G Ho0.
SbO3Na. (Sb03)oBa.
SbOtf (SbO3\>Mg.
Besides these there are the antimonates of strontium, calcium,
aluminium, manganese, iron, nickel, cobalt, and tin.
Antimony Pentasulphide, Sb2Sv—It is obtained by decomposing
the sulpho-salts with acids. It is called soufre dore d'aniimoine in
French, and Goldschwefel in German. It is generally obtained in a
pure condition from Schlippe's salt:—
2Na3SbS4 + 3HoS04=3NaoS04 + Sb^ + 3H A
or 2Na2SbS4 + 6HC1 = 6NaCl + 3H.2S + Sb.^
According to Bertsch and Harmsen we have:—
S4 + 3SbCl6=4Sb>2S5 +
10N"a3SbS4 + 30HC1+3Sb2O5=8SbIs5 + 30XaCl + 15H2O.
According to L. Prunier, the process is:—Fuse the trisulphide and
sulphur together. The product of fusion is boiled with a solution of
monosulphide of sodium. After nitration, the liquid is concentrated
for crystallisation. This salt is redissolved in a solution with excess
of acid. The pentasulphide is then precipitated.
The pentasulphide is easily dissociated: it loses its sulphur
component partially at 120°, and changes to the trisulphide if the
temperature is raised higher. Hydrogen reduces it (Hoffter). When
heated in air, it oxidises with a flame. It alters in humid air {Otto
and Jahn). Alkaline solutions change it to a mixture of sulphantimonate
and antimonate.
The most important salts of sulph-antimonic acid (HaSbS4) are:—
SbS4Ba3.6H2O. SbS^-f 9H2O.
•(SbS4).2Cd3.
SbS4K3+4H2O.
With other elements we have :—
Sb2Se5, antimony pentaselenide.
Antimony arsenate.
., phosphate.