Here in this example question it says identify the half reactions from the following redox reaction. So here we have permanganate plus sulforous acid producing manganese 2 ion plus bisulfite ion. All right.
Remember to get the half reactions we look for elements that are not oxygen or hydrogen. So we can see here we have manganese with manganese, so that would represent 1/2 reaction. So we'd have
MnO 4 - ( aq ) → Mn 2 ( aq )Then we can see that the other element that is not oxygen or hydrogen is sulfur. So here we have sulfurous acid giving us by sulfate ion. So these will represent our two half reactions.