Effect of ultrasound on the redox reactions of iron (II) and (III)

2098-2101The standard electrode potential of Fe3+/Fe2+ (+0.77V) is very close to the mid-point value of 0.8V in the electrode potential series. The oxidation and reduction of iron from oxidation state II to III and vice versa is therefore possible theoretically with equal case. This has been examined experimentally and the phenomenon of cavitation, generated through ultrasound, is found to facilitate both oxidation and reduction reactions of iron. Under ultrasonic field a solution of Fe(II) oxidizes to Fe(III) and forms a pink coloured complex of [Fe(SCN)6]3- whereas Fe(III) reduces to Fe(II) and complexes with K3[Fe(CN)6]to form a prussian blue solution. A possible mechanism for inter-conversion has also been discussed