77l HALOGEN COMPOUNDS.
Distil the antimony trichloride solution from a retort, provided
with a thermometer, until the temperature reaches 120°; in order
to prevent bumping, place bits of pumice or of unglazed porcelain
in the liquid. The distillate consists chiefly of hydrochloric acid,
containing eventually some arsenic trichloride.
Transfer the liquid remaining in the retort, after again filteringthrough asbestos if necessary, to a distilling flask. Fit the side
arm of the latter by means of a cork stopper to a long tube
about 1 cm. in diameter which serves as a condenser (cf. Fig. 8,
p. 7). The distillate first passing over is clear, then becomes
more or less yellowish due to ferric chloride, and finally, when the
temperature is above 215°, it becomes colorless again. At this
point change the receiver for a dry, clean, weighed Erlenmeyer
flask. The last portion of the distillate solidifies, on cooling, into
a radiating mass of crystals. It can be further purified by redis-
tillation. Boiling-point, 223°.
Pour the first fraction of the distillate, which consists of a mix-ture of hydrochloric acid and antimony trichloride, into a large
quantity of water; collect the precipitated basic antimony chloride
(essentially a mixture of SbOCl and Sb 2 O 3 ) on a filter and wash
and dry it. Dependent preparation: Metallic Antimony, No. 7.
Antimony Pentachloride. Pass dry chlorine gas into fusedantimony trichloride until the gain in weight corresponds to that
required for the change to the pentachloride. At first the reaction
mixture must be kept above the melting-point of pure trichloride,
but as more and more of the pentachloride, which is liquid under
ordinary conditions, forms, the mixture may be allowed to cool to
room temperature. Concerning the preparation of the beautifully-
crystalline salicylic acid methyl ester of antimony pentachloride,
C6H4(OSbCl4)CO 2 CH 3 , see A. Rosenheim and W. Loewenstamm,Ber. 35, 1126 (1902).
- Iodides of Bismuth.
Bismuth Tri-iodide. Triturate 8 g. of sifted, powdered bismuth
with 13 g. of iodine in a mortar, and introduce the mixture into a
50 c.c. plain retort. Cut off the neck of the retort to a length of
about 7 cm., and suspend the whole with a loop or spiral of wire
from a ring-stand in such a way that all portions of the retort can
be heated freely. On heating the mixture a feeble reaction is soon
observed. On heating more strongly, a little iodine sublimes at