The number of autocatalytic cycles (i.e., the cyclic mechanism indicated by the red arrows in Scheme 3) resulting per electron needed to electrogenerate S2O8 , Q = 6.17 C) yielded ns = 1.94 ± 0.03, as expected for the overall 2e -reduction of S2O8 2-, eq 10. When the experiment was repeated in the presence of 200 mM C2O4 2-(Figure , Q = 2.32 C) ns decreased significantly to a value of 0.42 ± 0.01, indicating that some fraction of S2O8 2-is being consumed by the autocatalytic reaction, thereby reducing the electrical charge required to reduce all S2O8 2-in solution.