538 Gooch and Soderman — Barium and Strontium. 



Art. XXII. — A Method for the Separation and Deter- 

 mination of Barium Associated with Strontium; by 

 F. A. Gooch and M. A. Soderman. 



(Contributions from the Kent Chemical Laboratory of Yale Univ. — cccii.) 



It has been shown by Mar, in a former article from this 

 laboratory, 1 that barium may be separated quantitatively 

 from calcium and magnesium by dissolving the mixed 

 chlorides in the least possible amount of water and throw- 

 ing the barium out of solution as the hydrous chloride by 

 the addition of a 4:1 mixture of concentrated aqueous 

 hydrochloric acid and ether, the calcium and magnesium 

 remaining in solution. The following account gives the 

 outcome of an attempt to adapt this procedure to the 

 similar separation of barium from strontium. 



The results of preliminary experiments showed plainly 

 that the procedure found by Mar to be satisfactory for 

 the separation of barium from calcium and magnesium 

 yields high indications for barium when strontium is 

 present even in moderate amounts. 



It has been found, however, that excellent results may 

 be attained by a modified procedure. The success of the 

 operation depends upon so adjusting the amounts of the 

 water and of the aqueous hydrochloric acid and ether 

 mixture that the barium chloride shall be as insoluble 

 as possible while strontium chloride, in reasonable 

 amount, shall be completely dissolved. Without describ- 

 ing in detail many experiments with varying amounts of 

 the water, acid, and ether used in the process, as well as 

 experiments in which alcohol was also introduced (with- 

 out beneficial effect), it will be sufficient to indicate the 

 procedure by which good analytical separations of 

 barium and strontium may be accomplished surely and 

 easily. 



It has been found that the proportion of water in the 

 mixture may be regulated properly by dissolving the 

 mixed chlorides in the least possible amount of water 

 and adding a suitable amount of a 4: 1 mixture of 33% 

 hydrochloric acid and ether. Under such conditions the 

 barium chloride is precipitated and strontium chloride 

 dissolves. It has been found that the solubility of barium 

 chloride after solution in the least possible amount of 



1 This Jour., (3) 43, 521, 1892. 



