Unreacted iodobromine (or iodine monochloride) is reacted with potassium iodide which converts it to iodine, whose concentration can be determined by titration with sodium thiosulfate.
Unreacted iodobromine (or iodine monochloride) is reacted with potassium iodide. This potassium iodide converts it to iodine. Iodine's concentration can be determined by titration with sodium thiosulfate.