Dynamical processes in which many timescales coexist are called dispersive. The rate coefficients for dispersive processes depend on time. In the case of a chemical reaction, the time dependence of the rate coefficient, k(t), termed the specific reaction rate, is rationalized in the following way. Reactions by their very nature have to disturb reactivity distributions of the reactants in condensed media, as the more reactive species are the first ones to disappear from the system. The extent of this disturbance depends on the ratio of the rates of reactions to the rate of...