rine and ultimately
give a residue of antimony trioxide. It combines with chlorides of the
alkali metals to form double salts, and also with barium, calcium,
strontium, and magnesium chlorides. Antimony pentachloride, SbCl5 is
prepared by heating the trichloride in a current of chlorine. It is a
nearly colourless fuming liquid of unpleasant smell, which can be
solidified to a mass of crystals melting at -6 deg.C. It dissociates
into the trichloride and chlorine when heated. It combines with water,
forming the hydrates SbCl5.H2O and SbCl5.4H2O; it also combines with
phosphorus oxychloride, hydrocyanic acid, and cyanogen chloride. In
chloroform solution it combines with anhydrous oxalic acid to form a
compound, Sb2Cl8(C2O4), which is to be considered as
tetra-chlorstibonium oxalate

COOSbCl4
|
COOSbCl4

(R. Anschutz and Evans, _Annalen_, 1887, ccxxxix. 235). Antimonyl
chloride, SbOCl, is produced by the decomposition of one part of the
trichloride with four parts of water. Prepared in this way it contains
a small quantity of the unaltered chloride, which can be removed by
ether or carbon bisulphide. It is a white powder insoluble in water,
alcohol and ether. On heating, it is converted into the oxychloride
Sb4O5Cl2 (Sb2O3.SbOCl). Antimony oxychloride, SbOCl3, is formed by
addition of the calculated quantity of water to ice-cooled antimony
pentachloride, SbCl5 + H2O = SbOCl3 + 2HCl. It forms a yellowish
crystalline precipitate which in moist air goes to a thick liquid.
Compounds of composition, SbOCl3.2SbCl5 and SbO2Cl.2SbOCl3, have also
been described (W.C. Williams, _Chem. News_. 1871, xxiv. 234).

Antimony tribromide, SbBr3, and tri-iodide, SbI3, may be prepared by
the action of antimony on solutions of bromine or iodine in carbon
bisulphide. The tribromide is a colourless crystalline mass of
specific gravity 4.148 (23 deg.), melting at 90 deg. to 94 deg. C. and
boiling at 275.4 deg. C. (H. Kopp). The tri-iodide forms red-coloured
crystals of specific gravity 4.848 (26 deg.), melting at 165 deg. to
167 deg. C. and boiling at 401 deg. C. By the action of water they
give oxybromides and oxyiodides SbOBr, Sb4O5Br2, SbOI. Antimony
penta-iodide, SbI5, is formed by heating antimony with excess of
iodine, in a sealed tube, to a temperature not above 130 deg.C. It
forms a dark brown crystalline mass, melting at 78 deg. to 79 deg. C.,
and is