The kinetics of the electron transfer reaction between iron(II) and bright platinum electrodes was studied in 2N sulfuric acid and in sulfuric acid containing azide, bromide, chloride, oxalate, thiocyanate and tetrafluoroborate ions. The chloride, bromide, and azide ions were shown to function only as blocking agents for the electron transfer reaction. An increase in the measured current on the addition of oxalate ion was attributed to the formation of an iron(III) complex which increased the rate of desorption of the oxalate from the electrode, thus cleaning the electrode. The results indicated that thiocyanate served as an electron transfer bridge, while tetrafluoroborate increased the rate, probably by ion pairing.