524 



F. W. Mar — Determination of Barium 



Exp. 



29. 



30. 



31. 



32. 



33. 



34. 



35. 



36. 



3 7. 



38. 



39. 



40. 



BaClo.2H 2 0. 



5001 grin. 

 4999 " 

 5005 " 



5002 " 

 5001 " 

 5005 " 

 5001 " 

 5001 " 

 5G03 " 

 1002 " 

 0107 " 

 5100 " 



0aCl 2 



0'5 o-rrn. 50 cm 



Series F. 

 HC1. Ether. 



0-5 



0-5 



0-42 



0-5 



0-5 



0-5 



05 



0-5 



3-0 



3-0 



0-5 



50 



25 

 25 

 25 

 25 

 25 

 25 

 25 

 25 

 25 

 25 



10 cm 3 

 10 " 



25 " 



5 " 



5 " 



5 " 



5 " 



5 " 



5 « 



BaClo. 

 0-4250 grm. 



0-4250 " 



0-4260 " 



0-4258 " 



0-4255 " 



0-4251 " 



0-4254 " 



0-4258 "• 



0*4261 " 



0-0842 " 



0-0080 " 



0-4328 " 



Loss. 

 0001 3 grm. 



0-0011 " 



0-0006 " 



0-0004 " 



0-0008 " 



0-0015 " 



0-0009 " 



0=0005 " 



0-0004 " 



0-0010 " 



0-0005 " 



0-0020 " 



Series F was undertaken to test whether the mode of pre- 

 cipitating barium used in the preceding series would be of use 

 in the separation of the barium from calcium. The experi- 

 ments were conducted as in Series E, except that the calcium 

 salt was dissolved with the barium chloride. It was necessary 

 to use more water than in Series E to .effect solution, but as 

 the barium salt was uniformly the last to dissolve the effect 

 was practically the same as before. The results show that 

 mixtures of barium and calcium in all proportions are per- 

 fectly separated by this method, 010 grm. of barium chloride 

 being separated with accuracy from 3 grm. of calcium chloride. 

 The calcium does not show the slightest tendency to come 

 down with the barium, and those experiments in which sepa- 

 ration was effected by the use of 25 cm 8 of hydrochloric acid 

 and 5 cm 3 of ether gave rather better results than those in 

 which double this volume was employed. It is better not to 

 let the precipitations stand too long before filtration, even if 

 kept cold, as the hydrochloric acid evaporates from the solu- 

 tions, and experiments in which filtration was delayed for 

 about two hours (e. g., Exps. 33, 34, 35) show a rather larger 

 loss than the average. That there is no advantage in increas- 

 ing the amount of ether over the proportions used above is 

 shown by Exp. 31 which is comparable with Exp. 25. In the 

 case of Exp. 40, in which no ether was used the result is com- 

 parable with the experiments of Series A. The precipitate 

 was washed, however, with the mixture of hydrochloric acid 

 and ether. 



Sesies G-. 

 Exp. BaCU . 2H20. MgCl 3 . 6H0 2 . HC1. Ether. BaClo. Loss. 



41. 0-4999 grm. 0-5 grm. 25 cm 3 5 cm 3 0-4253 grm. 0*0007 grm. 



42. 0-5000 " 0-5 " 25 " 5 " 0-4257 " 0-0005 " 



43. 0-1002 " 3-0 " 25 " 5 " 0'0844 " 0-0008 " 

 45. 0-0100 " 3-0 " 25 " 5 " 00077 " 0-0008 " 



