This is an interesting reaction with quite drastic color changes. It is also one of the few known oscillation reactions. I followed the prepartion guide from this website: http://chemistry.about.com/cs/demonstrations/a/aa050204a.htm The information about the reaction mechanism I got from this site: http://www1.chem.leeds.ac.uk/delights/texts/expt_11.html I did not mention it in the video, but the manganese sulfate is added to provide Mn2+ ions. These Mn2+ ions catalyze 2 steps of the radical