Separability versus Nonseparability of Effects

In equation 4.1-3, the effects of the various reaction parameters (c, T) are separable. When mechanistic considerations are taken into account, the resulting rate law often involves a complex function of these parameters that cannot be separated in this manner. As an illustration of nonseparability, a rate law derived from reaction mechanisms for the catalyzed oxidation of CO is 

In this case, the effects of cco, Cq2, and T cannot be separated. However, the simplifying assumption of a separable form is often made the coupling between parameters may be weak, and even where it is strong, the simpler form may be an adequate representation over a narrow range of operating conditions. 

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