Rate of the reaction in pure modes

Theorem.- In a pure mode, the rate of the reaction is the product, balanced by the reverse of the multiplying coefficient, of the reactivity of the rate-determining step (other steps being at equihbrium) and the space function relating to the zone where the rate-determining step proceeds. 

To calculate the rate of the reaction (as the pure mode is a pseudo-steady state one), it is enough to apply relation [7.33] choosing the rate-determining step as step i and thus we will have  

at constant physicochemical conditions, the solution is put in the form of a product of reactivity, independent of time, and a space function that can 

In this case specifically, we can then speak of the reactivity and of the space function of the general reactiom 

---