J . Phys. Chem. 1990, 94, 3636-3639
3636
reasonable based on the similarity with the potentiostatic case to suggest that the square-wave response for the homogeneous and heterogeneous pathways would be indistinguishable for log (kt,) < -0.4.4 On the other hand, the charge-transfer step is Nernstian for log [ k l o ( t p / D ) ] l > Z ]0.6. Combining these criteria together with a reasonable value of D (9 X lod cm2/s), log ( k , o / k 1 / 2>) -1.7. This criterion should provide a general guide to the range of utility of this model for E l o
