Associated with Calcium and Magnesium. 



213 



Experiment I Experiment II 



Weight Loss Weight Loss 

 grm. grm. grm. grm. 



BaCl 2 .2H 2 taken 0-1012 0M000 



(a) Residue after precipitation, 



washing, and drying in air, 0-1008 0-0004 0-0996 0-0004 



(b) Residue after treatment with 



acetyl chloride, washing, 



and drying in air 0-1006 0-0002 0-0996 O'OOOO 



(c) Residue after treatment with 



acetone-acetyl chloride mix- 

 ture, washing, and drying 

 in air.. 00985 0-0021 0*0981 0-0015 



(d) Residue after heating, BaCl 2 0'0846* 0'0839f ' 



BaCl 2 .2H 2 corresponding to 

 Bad, found O-0993 0-0985 



Loss of BaCl 2 .2H 2 due to 

 solubility and dehydration 0-0027 0-0019 



Loss of BaCI 2 .2H 2 due to 

 solubility, calculated from 

 BaCI 2 .2H 2 taken and BaCl 2 

 found 0-0019 0-0015 



Loss by dehydration 0-0008 0-0004 



* Heated to low redness. f Heated to 135° for 1^ hrs. 



From these results it appears (a) that when the acetone- 

 acetyl chloride mixture (4 : 1) acts upon the cooled concen- 

 trated water solution of barium chloride the precipitate is the 

 hydrous chloride, BaCl 2 .2H 2 0, only the water in excess of that 

 needed to form the hydrous salt being immediately attacked ; 

 (b) that acetyl chloride by itself produces only slight dehydra- 

 tion of the salt without marked solubility ; and (c) that pro- 

 longed action of the acetone-acetyl chloride mixture (2:1) 

 results in appreciable dehydration and considerably increased 

 solubility of the salt. By further experimentation it was 

 shown that when the acetone-acetyl chloride mixture is added 

 without cooling to the water solution of barium chloride the 

 heat of reaction favors dehydration of the hydrous salt, and 

 the anhydrous salt may go into solution to the amount of 

 several milligrams in 10 cm3 of the precipitating mixture. Upon 

 filtering the mixture and. treating the filtrate with acetone, 

 with acetyl chloride, or with the acetone-acetyl chloride mix- 

 ture the dissolved anhydrous salt is not thrown out of solution, 



