258 



Oooch and Cole — Chlorine in Haloid Salts. 



work to be described, telluric acid was prepared by acting 

 with chlorine upon finely divided elementary tellurium sus- 

 pended in water.* Solutions of iodine and of sodium thio- 

 sulphate of approximately N/10 strength were carefully stand- 

 ardized, the iodine against N/10 arsenite and the thiosulphate 

 against the iodine with the use of starch as an indicator. A 

 thiosulphate solution of N/50 strength, for use in the titration 

 of very small amounts of iodine, was prepared by suitably dilut- 

 ing the N/10 solution of that reagent. The potassium bromide 

 used was made by ignition and thorough fusion of potassium 

 bromate specially prepared from purified bromine and potassium 

 hydroxide. The potassium chloride was made by ignition of 

 the pure chlorate. These salts were kept over sulphuric acid 

 in a desiccator and were weighed directly for each determina- 

 tion. 



Fig. 1. 



The apparatus used for the distillation and absorption of 

 liberated bromine, shown in the accompanying figure, was 

 made with sealed or ground-glass joints throughout by sealing 

 a separating funnel A to a Yoit flask B, the outlet tube e of 

 the latter to the inlet tubeyof a Drechsel wash-bottle C, and 

 the outlet tube of the last to a bulbed trap g. The Yoit flask, 

 which served as the distillation flask, was graduated with 

 etched lines at 5 cm3 intervals, to indicate by the position of the 

 liquid meniscus volumes ranging from 5 cm3 to 50 cm3 . The 

 Drechsel bottle, with the trap, served as a receiver of the dis- 

 tillate, and this was kept cool by immersion in ice- water. A Kipp 

 generator for the delivery of washed carbon dioxide was con- 

 nected, as needed, with the separating funnel. 



In the following tests, the alkali halides and the telluric acid 

 were introduced in solution into the graduated flask and the 

 * Browning and Minnig, this Journal (4), xxxvi, 72, 1913. 



