In an @E01960@, when reactants or @I03096@ are adsorbed, the @R05156@ may no longer be related to the @C01222@ by a simple law. The @D01650@ may be due to either entropic or energetic effects or both. The situation best understood is that where a reactant is non-specifically adsorbed in the outer Helmholtz plane (inner boundary of the @D01714@). The effect of such @A00155@ on electrode kinetics is usually termed the Frumkin effect. @O04322@, transfer coefficients etc. corrected for this effect are frequently called 'true' rate constants etc. It would be preferable to describe them as 'corrected for the Frumkin effect', but in any case, if such a correction is carried out, the basis on which it is made should be clearly described.