Activation energies of unimolecular surface reactions

The dependence of the rate constant of eq. (10.19) on the temperature should take the form of the Arrhenius equation. 

The temperature dependence of the equilibrium constant K will foUow the van t Hoff relationship 

Here A (7° is the standard molar internal energy change in the adsorption process. At low pressures, since the rate of reaction is v = kK[jk], the overall rate constant for this process is simply 

The apparent activation energy, , for this first-order reaction is thus 

At high concentrations of the reactant, the rate follows eq. (10.20), and the observed activation energy is simply 

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