A Comprehensive Treatise on Inorganic and Theoretical Chemistry

262 INORGANIC AND THEORETICAL CHEMISTRY
black begins to deposit on the glass. The treatment occupies about 20 mine. Extract
the greyish-yellow mass in a beaker with 20 c.c. of boiling water ; and filter the hot pale
yellow soln., from the black residue. On cooling, a mass of pale yellow crystals of the
trans-salt is deposited from the soln. Drain the crystals, wash with alcohol, then with
ether, and allow them to dry. Yield O-1 grm.
The colour of the trans-salt ranges from a pale yellow to a sulphur yellow.
It may occur in acicular crystals, or, according to A. Cossa, in rhombic, hexagonal
plates. A. M. Boldyreva said that the crystals are tetragonal and uniaxial.
H. D. K. Drew and co-workers found that the pale yellow crystals are tabular, and
often elongated, and twinning is common. The crystals have a straight extinction ;
positive elongation ; and refractive index 1*76. M. Peyrone said that the salt
decomposed at about 270° into ammonium chloride, hydrogen chloride, nitrogen
and platinum. J. Lifschitz and E. Rosenbohm studied the optical properties.
A. Werner and A. Miolati found the mol. conductivities of soln. with a mol of the
salt in 5OO and 1000 litres of water are respectively 22-6O and 22-42. A. Werner
and C. Herty said that the electrical conductivity of the soln. is characteristic of
that of a n on-ionized salt. H. D. K. Drew and co-workers found that the conductivity
increases rapidly with time, so that the mol. conductivities, /z, of soln.
with a mol. of the j8-salt in 2866 and 1234 litres, respectively, were :
Time . . . O 62 131 174 2752
Jv = 2866 . . 7-0 21O 261 32-7 89-8
t*{v= 1234 . . 7-5 9-O 11-2 14-1 38-7
They attributed the change to the destructive action of water generating ammonium
chloride. A. Werner and A. Miolati made observations on the conductivity of
soln. of the salt. The salt dissolves very slowly in water. W. Odling observed that
the salt is very sparingly soluble in cold water ; but is more soluble in hot water—
M. Peyrone observed that ] 40 parts of boiling water dissolve 1 part of salt, and
P. T. Clove, that 13O parts of boiling water or 4472 parts of water at 0° are required
to dissolve 1 part of salt. H. D. K. Drew and co-workers said that 100 grms. of
water at 25° dissolve 0-036 grm. of the a-salt. The treatment of the salt with
chlorine, aqua regia, or a mixture of potassium chlorate and hydrochloric acid
furnishes citron-yellow, octahedra of platinic dichlorotetramminochloride ; biomine
furnishes a mixture containing platinous dibromodiammine, and similarl}*- with
iodine ; with hot nitric acid, yellow fumes are evolved. IJ. TschugaefE and W. Chlopin
found that Koiset's chloride in the presence of ammonia and ammonium carbonate
forms platinic; chloropentamminoehloride—vide infra, Peyrone/s chloride ; and
that with hydrogen dioxide, hydroxy-compounds are formed. The salt is converted
by aniline or ethylamine into platinous bisaniline diamminochloride or bisethylaminediamminochloride
respectively. An excess of potassium cyanide dissolves
the salt with the liberation of ammonia and the formation of potassium cyanidoplatinite.
IJ. Ramberg studied the liberation of ammonia from the platinum
ammines when they are treated with sodium hydroxide ; and I. I. Shukoff and
O. P. Shipulina, the adsorption of the salt by charcoal. A. Werner observed that
when the salt is triturated with silver oxide, the resulting colourless alkaline fluid
furnishes the trans-salt when treated with an excess of cone, hydrochloric acid.
P. T. Cleve said that a soln. of silver nitrate does not precipitate all the
chlorine. N. S. Kurnakoff found that thiocarbamide forms the complex salts
PtCl2{CS(NH2)2}4, PtCl2{CS(NH2)2}2, and PtCl2.CS(NH2)2 ; and that with pyridine
there is formed PtCl2{CS(NH2)2}2(C6H5N)2.
E. Koefoed reported that a brown salt of the same composition as that of the
yellow salt just described is formed by boiling yellow platinous tetramminochloride
with cone, hydrochloric acid ; and by boiling a cone. soln. of platinous tetramminochloroplatinite
in aq. ammonia, not too long with dil. hydrochloric acid, evaporating
the soln. to dryness, treating the residue with hydrochloric acid (sp. gr. 1-19) and
evaporating to dryness a few times, crystallizing from boiling water, and drying
at 100°. The leather-brown crystals are sparingly soluble in water, but they are