Abstract
Rapid methods for the drtermination of small amounts of chlorine in the bromine was investigated, and the following two procedures were developetd.
1) Direct method; A bromine sample was reduced to bromide with hydrogen peroxide or sodium sulfite. Then the chlorine in the bromine was reduced to chloride. Adding a small excess of potassium bromate to the solution, the bromide was oxidized to bromine, and it was extracted with carbon tetrachloride. The chloride remaining in the aqueous layer was determnied by the Volhard method. The presence of a large amount of potaseium bromate caused errortical results.
2) Indirect method; Potassium bromate was added to the reduced sample solution, and almost all bromide was oxidized. The bromine was extracted with carbon tetrachloride and the aqueous layer was made up to the definite volume. The solution was divided into two aliquots. The sum of bromide and chloride was determined by Volhald method in an aliquot. The bromide was determined in the other, treating the solution with sodium hypochlorite and titrating the bromate iodometrically. The accurate result was obtained, when the molar ratio of bromide to chloride ion was smaller than 2.
From 0.2 to 1 percent of chlorine in bromine could be de termined accurately by the above procedures.
