A Comprehensive Treatise on Inorganic and Theoretical Chemistry

28O INORGANIC AND THEORETICAL CHEMISTRY
tates when heated, but not so if it has been previously dried. J. Petersen found the
lowering of the f.p., and the calculated mol. wt. :
K2PtC]- . . 1-150 2-532 3-147 7-715 per cent.
Lowering f.p. . . O-145° 0-290° 0-355° 0-900°
MoI. wt. . . 357 395 399 386 Theory, 415
The calculated values for the J. H. van HofT's coeff.—1. 15, 10—range from 2-32
to 2-96. J. Thomsen found the heat of formation (Pt, Cl2, 2KC1) ==45-17 CaIs. ;
(Pt, Cl2, 2KCl, Aq.)=41-8 CaIs. ; and the heat of soln., —12-22 CaIs. J. Lifschitz
and E. Rosenbohm studied the optical properties ; D. P. Mellor and F. M. Quodling,
the birefringence ; S. Aoyama and co-workers, the X-ray spectrum ; and
R. Samuel and co-workers, the absorption spectrum. A. Werner and A. Miolati
measured the mol. conductivity of soln. with a mol of the salt in v litres, at 25°,
and observed :
v 25O 5OO 10OO 2000
fi. 251-6 260-4 267-6 279-3
N. Demassieux and J. Heyrovsky studied the dissociation of the salt in soln. ;
E. R. Smith, the potential of the chloroplatinate-chloroplatinite electrode ;
W. Schneider, the piezoelectric effect. E. Feytis gave for the magnetic susceptibility,
—0-356 Xl0~ 6 mass unit. E. Rosenbohm studied the subject. G. Magnus
said that the salt readily dissolves in water, forming a reddish-yellow soln. ; and
W. Crookes observed that 1OO parts of water dissolve 0-926 part of the salt at 16°,
and 5-263 parts with boiling soln. According to J. Lang, a soln. of the salt is
Qoloured brownish-black by hydrogen sulphide, and with hot soln., a black precipitate
is formed ; ammonium sulphide gives a black precipitate. W. Peters
observed that no ammonia is absorbed by the dry salt ; and J. Lang, that with
aq. ammonia, green platinous tetramminochloropJatinite is formed ; ammonium
carbonate also decolorizes the hot soln. H. D. K. Drew and co-workers symbolized
the reaction with ammonia : K2PtCl4-*K2Pt(NH3Cl) Cl3-> Pt(NH3Cl)Cl ; and by
K2PtCl4^ K2Pt(NH3Cl)2Cl2-^ Pt(NH3Cl)2. A. Sieverts studied the action of sodium
hypophosphite on dil. soln. of potassium chloroplatinite resulting in the formation
of colloidal soln. of platinum. M. Vezes observed that potassium nitrite forms a
chloronitrite. E. Biilmann and A. C. Andersen found that allyl alcohol makes the
red soln. pale yellow, and K[Pt(C3H5OH)Cl3J is formed. K. Birnbaum showed
that complex salts are formed with ethylene, propylene, and amylene ; E. Koeofed,
that dimethylamine forms [Pt{(CH3)2NH}2Cl2J, and diethylamine gives a precipitate
mainly of platinum black ; and N. S. Kurnakoflf, that acetamide, with a warm
soln., forms blue and violet colours, and propionamide, butylamide, capronamide,
succinimide, and phthalimide give blue colours, whilst thiourea furnishes complex
salts, and guanidine or guanidine carbonate, in boiling soln., gives a greenishblack
precipitate. J. Lang found that a soln. of potassium hydroxide has no
reaction on a hot or cold soln. of the salt, but potassium and sodium carbonates
produce a black precipitate which settles very slowly. H. Schwarz studied some
reactions of the salt; and A. Griinberg, the nature of the trans-effect with the
PtCl'Vions.
L. F. Nilson prepared rubidium chloroplatinite, Rb2PtCl4, by adding hydrochloroplatinous
acid to a soln. of rubidium chloride, drying the salt on a waterbath,
extracting the salt with water, drying the salt between bibulous paper and
then over sulphuric acid or at 100°. R. Bottger passed hydrogen sulphide through
a soln. of rubidium chloroplatinate until half the platinum is precipitated, and
evaporated the nitrate. The red, or brownish-red, four-sided prisms are stable
in air. L. F. Nilson said that the salt is sparingly soluble in cold water and freely
soluble in hot water ; and W. Crookes added that 100 parts of water dissolve
0-135 part of salt at 15-5°, and 0-637 part in boiling water. L. F. Nilson also prepared
caesium chloroplatinite, Cs2PtCl4, by adding caesium sulphate to a soln.
of barium chloroplatinite. L. Wohler and F. Martin reduced a soln. of hydrochloro-