We confine ourselves to the case of fast mobility of reagents in a mixture consisting of s components, when they are equilibrated over the sites of a uniform surface [10]. The stages of adsorption, desorption, or chemical transformations involving adsorbed particles can be limiting. Let the elementary stage of the chemical transformation A ↔ B be realized, which corresponds to the equality of rates in the forward and backward directions UA(α) = UB(α) – the symbol α corresponds to a certain stage number in the general multistage process. In conditions of complete equilibrium all stages must be in dynamic equilibrium. With the example of expressions in QCA, we show that the expressions obtained for the reaction rates are selfconsistent with a description of the equilibrium state of the reaction systems. That is, equating the rates of direct and reverse directions of each stage of the general process, we obtain the equations of the equilibrium distribution of particles.