The anodic oxidation of sulphite ions in alkaline 1 M Na2SO4 solution on gr
aphite rotating disc electrodes has been studied over the range from 25 to
60 degrees C. The reaction order with respect to sulphite ions is below 1 a
t low potentials and 1 at high potentials. The reaction order with respect
to hydroxide ions is close to zero. Two Tafel slopes were observed, 0.060 V
decade(-1) at low potentials and 0.190.20 V decade(-1) at high potentials.
The reaction activation energy was calculated at different potentials. The
results obtained, using the potential sweep method, are consistent with th
ose realized using the rotating disc. A possible reaction mechanism has bee
n proposed and the diffusion coefficients of sulphite ions and the diffusio
n activation energy have been calculated.