Abstract:
The kinetics of the oxidation of dithionate ion, S2O6 2-, by N,N/-ethylenebis [salicylideneiminato] iron (III) complex ion,[FeSalen(H2O)2]+, has been investigated at 28.5oC over aqueous perchloric acid concentration range of 0.05 > [H+] > 0.001 mol/dm3. Reduction of [FeSalen(H2O)2]+ was followed spectrophotometrically at 515nm. Spectrophotometric titration indicated that two moles of the oxidant was consumed for every mole of the reductant that was oxidized. Under pseudo-first order conditions of a large excess of dithionate ion,the rate of reaction increased with increase in concentration of dithionate ion but was invariant with variation in the concentration of the oxidant. The reaction is first order with respect to dithionate ion but zeroth-order with respect to [FeSalen(H2O)2]+ giving the rate as [ ][ ]. [ ] 2 2 2 6 1 − + − = K S O H dt d FeSalen The rate constant has a value of 1.92 x 10-2dm3mol-1s-1
