A Comprehensive Treatise on Inorganic and Theoretical Chemistry

PLATINUM 35
and K. A. Dologoff, Journ. Muss. Phys. Chem. Soc., 61. 1377, 1929 ; L. N. Vauquelin,
Phil. Mag., (1), 44. 33, 1814; Ann. Phil., 4. 216, 1814; Ann. Chim. Phys., (1), 88. 167,
1814 ; (1), 89. 150, 225, 1814 ; I. Wada and T. Nakazono, Bull. Inst. Phys. Chem. Research
Tokyo, 1. 139, 1923 ; I. Wada and S. Saito, ib., 8. 749, 1929 ; T. WiIm, Ber., 18. 2536,
1885 ; Journ. Muss. Phys. Chem. Soc., 17. 451, 1885 ; 18. 69, 1886 ; F. Wohler, Ann. Chim. Phys.,
(2), 54. 317, 1833 ; Liebig's Ann., 9. 149, 1834 ; Pogg. Ann., 81. 161, 1834 ; L. Wohler and
L. Metz, Zeit. anorg. Chem., 149. 297, 1925 ; W. H. Wollaeton, PhU. Trans., 99. 189, 1809 ;
Nicholson's Journ., 25. 18, 1810 ; Phil. Mag., (1), 88. 250, 1809 ; (1), 35. 164, 1810 ; M. Wunder
and V. Thuringer, Zeit. anorg. Chem., 52. 740, 1913 ; Ann. Chim. Phys., (8), 80. 164, 1913.
§ 5. Qualitative Recognition of the Platinum Metals
F. Mylius and R. Dietz gave a plan in -which the mixed chlorides are boiled in a
distilling flask 'with dil. nitric acid and the distillate collected in a soln. of sodium
hydroxide. If osmium is present, the liquid becomes yellow since osmium tetroxide
distils over -with the steam. The residual liquid is shaken with ether to extract
any gold chloride which collects in the ethereal layer. The liquid is then boiled
with ammonium acetate and formic acid for several hours in a flask fitted with a
reflux condenser, and the black precipitate is washed, dried, and heated to redness
in hydrogen. The residue is washed with hydrochloric acid, mixed with sodium
chloride, and ignited in chlorine. The product is dissolved in water and treated
with ammonium chloride, a precipitate contains the platinum, iridium, and
ruthenium, whilst palladium and rhodium remain in soln. (precipitates to left,
filtrates to right) :
Treat soln. with NH4Cl
1 ...
Add hydroxylamine to the hot aq. soln. Jilvaporate to dryness with excess NH4Cl ;
of precipitate and then NH4Cl extract with warm NH4Cl and cool
J. _ • I
Platinum Evaporate ; reduce dry Rhodium Palladium
residue in H2 ; fuse with
KOH -h KNO3 ; extract
with water
I
Mix with NaCl : heat Distil filtrate in Cla ;
in Cl2 ; add NH4Cl ; to volatilize RuO4
precipitate J
4, I
Iridium Ruthenium
Plans were also given by N". A. Tananaeff and K. A. Dolgoff, S. IT. Schemtschuschny
and co-workers, I. Wada and co-workers, and W. Graulich. S. C. Ogburg
gave the following gravimetric scheme for the separation of the six platinum metals
present as chlorides in dil. hydrochloric acid (7 to 8 c.c. HCl per 1OO c.c. of soln.) :
Add 1 per cent, alcoholic soln. of dimethyl glyoxime
in cold ; filter
4r I
Palladium, as Add excess 2 per cent, alcoholic soln. ot-furil-
Pd(C4H7O8Na)2
dioxime ; add alcohol IO per cent, of total
volume ; boil ; and filter
Platinum, as Concentrate soln. by evaporation ; add HCl
J?t(CX0H7O4Na)a
and NaClO8 to remove excess oximes ; add
alcoholic soln. KNO8 until liquid is alkaline ;
boil ; let stand over-night ; filter