Antimony with fiubidium. 273 



I have found that when solutions of antimony chloride and 

 rubidium chloride are mixed in the proportion of one and one- 

 iifth molecules of the former to one molecule of the latter a 

 pale yellow-salt is obtained crystallizing in rhombohedrons. In 

 one case on obtaining a crop of crystals from a solution of 

 2SbCl a to IRbCl, in strong HC1, the yellow rhombohedrons 

 were seen to be mixed with the colorless hexagonal plates, pre- 

 sumably of the salt 23RbCl . 10SbCl s ? It was also found that 

 a wide difference exists in the solubility of these two salts in 

 warm solutions, the yellow crystals dissolved with difficulty, 

 while on the other hand, the salt 23 : 10 went into solution 

 with only a slight elevation of temperature. If the crystals 

 of the yellow salt are warmed in the mother liquor they be- 

 come opaque throughout without losing their pale yellow color. 

 It seems probable that impurities are dissolved out by this 

 operation and that no decomposition takes place, for the decom- 

 position products and the other double chlorides are colorless. 

 An analysis of a crop obtained in this manner corresponded 

 very closely to the formula 3RbCl . 2SbCl 3 . Analysis gave : 





From 



solutions of 



2SbCl 3 to 



IRbCl. 



From 

 solutions of 

 liSbCls to 

 IRbCl. 



From 



solutions of 



2SbCl 3 to 



IRbCl 



heated. 



Calculated 



for 



3RbCl . 



2SbCl s . 



Calculated 



for 



5RbCl . 



3SbCl 3 . 



Rb 



32*57 32-19 



33'34 31-86 



31-30 



31-44 



33-28 



Sb 



28*68 28-67 



28-55 28-46 



29-44 



29-41 



28-03 



CI 



38*38 38-42 



38*32 



38-98 



39-15 



38-69 



23:10? Rubidium Antimony Chloride, 23 fib CI. 10SbCl % . 

 — For the preparation of this compound, a sample of rubidium 

 chloride was used which had been specially purified for the 

 purpose by the method recently described by Professor H. L. 

 Wells* of this laboratory. The purification of this sample 

 was repeated after the product failed to give spectroscopic 

 reactions for potassium and caesium. 



If solutions of antimony and rubidium chlorides are mixed 

 in the proportion of one molecule of SbCl, to one, four or 

 six molecules of RbCl, the crystals obtained are the " color- 

 less six-sided plates, tables, or thicker crystals,'' to which 

 Remsen and Saunders have assigned the formula 23RbCl . 

 lOSbClj. The average results of the analyses of the different 

 crops of the double chloride gave figures closely agreeing with 

 those of the above authors, but the ratio of rubidium to anti- 

 mony came somewhat lower than theirs. Analysis gave : 



* This Journal, III, xlvi. 188. 



Am. Jour. Sol— Third Series, Yol. XLVI, No. 274.— October, 1893. 

 19 



