380 



Messrs. R. Anschiitz and P. N. Evans. [June 16, 



investigation led to some important results concerning our knowledge 

 of the chemical nature of antimony pentachloride. 



Antimony pentachloride is well known to be an extremely hygro- 

 scopic body. Consequently in the application of La Coste's modifica- 

 tion of Victor Meyer's method for the determination of vapour- 

 densities under diminished pressure, it was necessary to substitute 

 liquid paraffin for water ; yet, in spite of numerous careful experiments, 

 we could not attain our object, the liquid paraffin offered too great a 

 resistance to the air, and before all the air had been driven out the 

 antimony pentachloride distilled into the upper and cooler parts of the 

 apparatus. During these experiments it was proved to us that it is 

 next to impossible to prevent the formation of traces of the white 

 substance, which is the result of the action of water on antimony penta- 

 chloride. We were accordingly constrained to put this method aside. 



Before attempting the determination of antimony pentachloride by 

 another method, we deemed it best first to find out the nature of the 

 error caused by the formation of the minute amount of the product 

 of water reacting on antimony pentachloride. 



After careful consideration we were struck by the contradiction 

 between the conclusions of Daubrawa* and those of R. Weber,f con- 

 cerning the behaviour of antimony pentachloride with water. Accord- 

 ing to the latter, antimony pentachloride forms with water a hydrate, 

 which is impossible if with 1 mol. of water antimony pentachloride 

 is changed in the cold to SbOCl 3 and 2 mols. of hydrochloric acid, as 

 Daubrawa thinks he has proved. 



The following results of our experiments show that Daubrawa's 

 statements concerning antimony oxy chloride, SbOCl 3 , are entirely 

 wrong. In connexion with these studies we have occupied ourselves 

 with the action of oxalic acid on antimony pentachloride, and have 

 succeeded in obtaining the remarkable product of this reaction in a 

 pure state. 



Reaction of Water on Antimony Pentachloride. 



Daubrawa allowed 1 part by weight of distilled water to drop from 

 a pipette into a flask, surrounded by ice, containing 16 parts by weight 

 of antimony pentachloride. He found the decomposition accompanied 

 by hissing, and by the formation of vapour, giving no white pulveru- 

 lent precipitate, but forming a yellowish distinctly crystalline mass, 

 which adhered to the flask. This crystalline mass, the behaviour of 

 which with water Daubrawa describes in detail, is, according to 

 his analysis, antimony oxychloride, SbOCl 3 , and he expresses its 

 formation from antimony pentachloride and water by the following 

 equation : — 



* 1 Liebig's Amialen,' vol. 186, 1887, p. 118. 

 f 1 Poggendorff, Annalen,' vol. 125, 1865, p. 86. 



