A frequency domain analysis of reversible molecular diffusion in a granule or relatively stagnant drop of fluid reveals that for the larger values of time the rate equation reduces to
Compared with an earlier time domain result
the rate predicted is 15/π2 = 1.516 greater and this has been confirmed by results of experiment. An analysis of time constants shows that the dimensionless group relation
defines mathematically that which is meant by the larger value of time limitation.