Thome —Barium Bromide by Hydrobromic Acid. 443 



The action of hydrobromic acid upon barium chloride was 

 next studied, with or without the presence of salts of calcium 

 and magnesium. 



A weighed amount of barium chloride, BaCl 2 . 2H 2 0, was 

 dissolved in the least volume of water and treated with a mix- 

 ture of hydrobromic acid and ether in equal volume. The 

 whole solution was saturated with hydrobromic acid gas, fil- 

 tered upon asbestos, and then, to make sure that no barium 

 oxy bromides might be formed, treated with ammonium bro- 

 mide, dried and weighed as BaBr 2 . 









Table IV. 







BaCl 2 . 



2H 2 



taken. 



CaC0 3 . 



MgC0 3 . 



HBr + 



ether 

 1:1. 



BaBr 2 

 found- 



Theory 



as 

 BaBr 2 . 



Error 



in 

 BaBr 2 . 



grm. 



grm. 



grm. 



cm 3 . 



cm 3 . 



grm. 



grm. 



0-2253 











30 



0-2744 



0-2741 



+ 0-0003 



0*2088 











30 



0-2538 



0-2540 



— 0-0002 



0-3273 









30 



0-3975 



0-3982 



-0-0007 



0-3177 











30 



0-3864 



0-3865 



—o-oooi 



0-5041 



0-5000 



. 



30 



0-6134 



0-6143 



— 0-0009 



0-5083 



0-5000 







30 



0-6185 



0-6191 



— 0-0006 



0-5046 



0-5000 







30 



0-6139 



0-G136 



+ 0-0003 



0-5022 



0-50O0 



. „ 



30 



0-6110 



0-6104 



+ 0-0006 



0-5018 



0-5000 







30 



0-6106 



0-6108 



— 0-0002 



0-5007 







0-3000 



30 



0-6087 



06092 



— 0-0005 



0-5048 







0-3000 



30 



0-6144 



0-6142 



+ 0-0002 



From these results it is obvious that barium may be separated 

 and determined as the bromide in presence of salts of calcium 

 and magnesium ; and it appears also that when the proportion 

 of hydrobromic acid to the barium chloride is that of the 

 experiment and the precipitate ignited with ammonium bro- 

 mide, the results are in practical accord with those which should 

 be obtained if the precipitate consists entirely of barium 

 bromide. 



On the other hand, it appears from the following series of 

 experiments that when a sufficiency of hydrochloric acid is 

 added to the water solution of barium bromide the pre- 

 cipitate falls practically as the chloride. 









Table V. 







BaBr 2 . 2H 2 



HC1 





BaCl 2 



Ba01 2 



Error in 



taken. 



used. 



Ether. 



found. 



theory. 



BaCl 2 . 



grm. 



cm 3 . 



cm 3 . 



grm. 



grm. 



grm. 



0-2044 



25 



5 



0-1279 



0-1277 



+ 0-0002 



0-2011 



25 



5 



0-1258 



0-1257 



+ 0-0001 



0-5021 



25 



5 



0-3138 



0-3138 



0-0000 



0-5037 



50 



10 



0-3148 



0-3147 



+ 0-0001 



0-5020 



25 



5 



0-3135 



9-3137 



— 0-0002 



0-3868 



25 



5 



0-2418 



0-2417 



+ 0-0001 



