522 F. W. Mar — Determination of Barium 



The experiments in Series A were made as follows : — The 

 barium salt was weighed out, placed in a small beaker and dis- 

 solved in the amount of water indicated. The barium was 

 then precipitated as the anhydrous chloride by adding, gradu- 

 ally at first, the amount of hydrochloric acid shown. After 

 standing for five or ten minutes the precipitates were filtered 

 off upon asbestos in Gooch crucibles, washed with concentrated 

 hydrochloric acid, dried sometimes over a low flame (at about 

 150°-200° C.) and sometimes in an air bath heated to 165° C. and 

 weighed. In several cases the total filtrate was measured and 

 the volume is given in the tabular statement. The results 

 show a considerable solubility amounting to about 1 part in 

 8000 under the conditions given. 









Series B. 







Exp. 



BaCl 2 .2H 2 



Water. 



HC1. Total filtrate. 



BaCl 2 . 



Loss. 



10. 



0*5057 grm. 



2 cm 3 



25 cm 3 75 cm 3 



0-4268 grm. 



0-0042 gim 



11. 



0-5017 " 



5 " 



50 " 90 " 



0-4198 " 



0-0078 " 



12. 



0-5068 " 



3 " 



50 " 100 " 



0-4235 " 



0-0085 " 



13. 0-5019 " 2 " 100 " 144 " 0'4186 " 0'0082 " 



The experiments in Series B were conducted similarly to 

 those of Series A except that the precipitates were allowed to 

 stand 24: hours before filtration. The loss due to solubility 

 was, as is shown by the table, greater than before, due doubtless 

 to the escape of hydrochloric acid gas from the solution. 



Series C. 



Exp. BaC] 2 .2H. 2 Water. HC1. Alcohol. BaCl 2 Loss. 



14. 0-5011 grm. 3 cm 8 25 cm 3 15 cm 3 0*4228 grm. 0-0043 grm. 



15. 0-5096 " 2 " 25 " 10 " 0'4278 " 0'0066 " 



The experiments of Series C were conducted in the same 

 manner as those of Series A except that the amount of absolute 

 alcohol indicated was added after the precipitation by hydro- 

 chloric acid. The results show that the alcohol neither de- 

 creased nor increased the amount of the solubility of the 

 chloride. 







Series 



D. 







Exp. 



BaClo.2HoO 



HC1. 





BaCl 3 . 



Loss. 



16. 



0-5019 grm. 



50 cm 3 





0-4249 grm. 



0-0029 grm 



17. 



0-5020 " 



50 " 





0-4257 " 



0-0022 " 



18. 



0-5020 " 



50 " 





0-4255 " 



0-0024 " 



19. 0-5016 " 50 " 0-4259 " 0-0017 " 



20. 0-5022 " 50 " 0-4267 " 0-0014 " 



In the experiments of Series D the weighed barium chloride 

 was placed in an Erlenmeyer beaker and dissolved in four or 

 five cubic centimeters of water. The indicated amount of acid 



