Reduction takes place in cathode while oxidation takes place at the anode. Given that the reaction 3MnO4- +24H + +5Fe→3Mn+2+5Fe+3+12H2O Now that oxidation is termed as an increase in oxidation number or loss of electrons while reduction is a decrease in oxidation number and gain of electrons, ∴oxidation will be Fe→Fe +3+3e- reduction will MnO4- +8H+ →Mn+2+4H2O If oxidation takes place at anode then Anode: an oxidation reaction Fe→Fe+3+3e- . Then the answer is Fe(s)→Fe+3(aq)+3e-