Further increases in the concentration of C2O4 2-result in a continuous decrease in the cathodic peak current and increase in the anodic peak current resulting in a reversible response resembling that of a solution containing only Ru(NH3)6 3+ (see Figure ). Thus, the CV results are consistent with the idea that eqs 17 and 18 initiate the S2O8 2-/C2O4 2-autocatalytic reaction (eq 1).