Homogeneous self-exchange reactions

The significance of these quantities is analogous to that for the activation parameters for homogeneous self-exchange reactions. Thus, AH equals the activation enthalpy for conditions... 

Relationships having the same form as eq 14 can also be written for the enthalpic and entropic contributions to the intrinsic free energy barriers (10). Provided that the reactions are adiabatic and the conventional collision model applies, eq 14 can be written in the familiar form relating the rate constants of electrochemical exchange and homogeneous self-exchange reactions (13) ... 

Also, the observed rates probably refer to outer-sphere pathways, and the rate constants for the corresponding homogeneous self-exchange reactions are available or can be estimated from rate data for closely related cross reactions (15). These h ex... 

Rate Constants and Thermodynamic Parameters for Selected Electrochemical Exchange and Homogeneous Self-Exchange Reactions at 25°C. 

The coefficient 2 in Eq. (h) arises because the free-energy profile for the homogeneous self-exchange reaction (f) will then equal the sum of those of the constituent forward and reverse electrochemical reactions (g). 

This equation also applies when the Ai terms are included (but work terms are neglected). This is the case because the total contribution to A j is summed over two reactants in the homogeneous self-exchange reaction, but only over one in the electrode reaction (61). 

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