Reaction MechanismsWatch this thread
The reaction is between potassium iodide and potassium peroxodisulfate. Also in the reaction is sodium thiosulfate and starch as an indicator.
The equation is below if it helps!
S2O82- (aq) + 2 I- (aq) -----> 2 SO42- (aq) + I2 (aq)
For the mechanism for the catalyst, the catalyst used was iron (II) sulphate.
Without checking electrode potential values, I seem to recall that the Fe2+ goes to Fe3+ (oxidised by the S2O82-). The Fe3+ then goes back to Fe2+ (oxidising the I- to I2).
That seems to be on the right track, I will have another look tonight, thanks for your help!