Tests For SO2 by keypoint Tests For SO2(g) Its irritating smell Action on oxidizing agents – It turns KMnO4(aq) from purple to colourless or KCrO7(aq) orange to green leaving no traces of sulphur. Others are Viewing: Sulphur (iv) oxide (SO2) Physical Properties of SO2 Chemical Properties of SO2 Uses Of SO2 Test For Chlorine Test For N2O Chemical Properties of Ammonia