FWS - The Iodine Clock Reaction

The iodide clock reaction is one of the classic chemical reactions you are shown in school/university. Two colourless solutions are mixed together and, in a given amount of time, the solution suddenly turns dark blue - almost black. There are several variations of the clock reaction but this video concentrates on the iodate version. The chemistry is rather difficult as there are multiple reactions going on. The first is in one of the clear solutions where bisulfate is generated when sodium sulfite (Na2SO3