A) IR: IR spectrum of sample should match with spectrum of working ref. Std. B) Iodide test: To 5 ml of a solution(1 in 1000) add 5 ml of sodium carbonate solution(1in 100), 0.5 ml of bromophenol blue, and 10 ml of chloroform, and shake for several minutes: the chloroform layer becomes an intense blue in color.