A Comprehensive Treatise on Inorganic and Theoretical Chemistry

298 INORGANIC AND THEORETICAL, CHEMISTRY
nitrate. W. Peters showed that anhydrous platinic chloride takes up 6 mols. of
dry ammonia, and that the resulting hexammine in vacuo loses a mol. of ammonia.
R. Silberberger found that the presence of platinum salts in dil. soln. does not affect
the precipitation of barium sulphate by the addition of barium chloride ; in cone,
soln. some platinic salt may be adsorbed by the precipitated barium sulphate.
H. Vohl, and W. Knop observed that in acidic soln. platinum salts give a precipitate
of platinous sulphide when they are treated with a soln. of sodium thiosulphate—
particularly with warm soln. ; and P. Schottlander, and P. Jochum, that in
ammoniacal soln., a complex platinous alkali thiosulphate is formed. M. C. Lea
observed that with an ammoniacal soln. of sodium thiosulphate, ammonium
chloroplatinate is first precipitated, and then, with heating, the soln. becomes
yellow, then colourless, and finally wine-red. C. Langlois observed that trithionic
acid gives a black precipitate ; M. C. Lea, that tetrathionic acid forms a wine-red
soln. ; F. Raschig, that sulphaminic acid produces no change in a soln. of hydrochloroplatinic
acid ; and J. A. Palmer, that ammonium thiocarbonate in
ammoniacal soln. along with ammonium chloride, gives a precipitate soluble in
excess. H. Rose, M. Delepine, and G. and W. van Dam noted that with ammonia
a precipitate of ammonium chloroplatinate is formed in soln. of platinic chloride,
and that the precipitate is soluble in excess when heated ; the precipitate is attacked
by chlorine ; 3Cl2+ (NH4)2PtCJ6 ^PtCl4+8HCl+N2. H. St. C. Deville and
J. S. Stas, S. M. Jorgensen, and S. A. Norton observed that ammonium chloride
slowly forms a precipitate with the aq. soln. at ordinary temp, or when heated.
T. Curtius and II. Schulz represented the reaction with hydrazine : 2PtCl4
+N2H4.H20===2PtCl2+4HCl+N2+H20. E. Knoevenagel and E. Ebler found
that hydrazine gives a precipitate in an ammoniacal or feebly acidic soln. and
hydroxylamine gives an incomplete precipitation in ammoniacal soln. N. Tarugi
studied the reaction with hydroxylamine ; and F. Reitzenstein observed that
hydroxylamine gives no precipitate with a cyanide soln. H. Rose found that
potassium nitrite precipitates potassium chloroplatinate from soln. of platinic
chloride, and that boiling the soln. produces no further change. H. Precht,
H. D. Rogers and M. H. Boye observed that a soln. of platinum in aqua regia
containing an excess of nitric acid furnishes platinic tetrachlorobisdinitrosylchloride,
[Pt(NOCl)2Cl4]—R. Weber recommended fuming nitric acid, and gave
the formula PtCl4.N2O3Cl2.H2O. S. M. Jorgensen obtained it by passing the
vapours from aqua regia into a cone. soln. of hydrochloroplatinic acid, and drying
the crystals at 100° ; and J. J. Sudborough, by the action of nitrosyl chloride on
platinum at 100°. S. M. Jorgensen said that the yellowish-brown crystalline powder
contains cubic forms. No water is lost at 100°, but stronger heating decomposes
the salt leaving platinum behind. The crystals are very deliquescent, and freely
soluble in "water. The salt decomposes in aq. soln. E. Baudrimont prepared a
complex with phosphorus pentachloride, namely, platinic tetrachlorodiphosphorichloride,
[Pt(PCl5)2C14]. R. Bottger observed that phosphorus, at ordinary temp.,
does not decompose soln. of platinum salts, but A. C. Christomanos observed that
a soln. of phosphorus in ether or benzene gives a precipitate with soln. of platinic
chloride. R. Bottger observed that phosphine does not give a precipitate with
soln. of platinic salt ; on the contrary, P. Kulisch found that with platinic chloride
soln., phosphine gives a lemon-yellow precipitate which soon becomes darker,
and finally, dark brown. R. Engel said that some platinous hypophosphite is
formed. G. Oddo found that anhydrous platinic chloride is soluble in phosphoryl
chloride. L. Vanino, A. Gutbier, and A. Gutbier and G. Hofmeier observed that
hypophosphorus acid does not precipitate platinum. M. C. Lea, and A. Atterberg
said that with hypophosphites platinic chloride is reduced to platinous chloride
and, added A. Sieverts and M. Major, the metal is not formed in hot or cold or in
acidified soln. but with very dil. -soln. of potassium chloroplatinite, and a large
excess (1 : 120) of a warm soln. of sodium hypophosphite. A. Sieverts and E. Peters
observed that a yellowish-brown colloidal soln. of platinum is formed. A. Rosen-