Hass action model chemical potentials defined

In Eq. (434) the interfreial electrostatic potential appears explicitly. The pseudo-standard state model would thus appear to be consistent wifli the BPD mass action equations 428 and 429. However, Eq. (433) has been derived under some very peculiar circumstances. Specifically, the chemical potentials in Eqs (432) and (434) are all standard state chemical potentials while the electrostatic Eq (433) is for variable, nonstandard states. Hence, it would seem that the derivation of adsorption equations by the pseudo-standard state method either violates thermodynamic principles or defines some very peculiar standard states. 

---