Significance of EA Determined at Controlled Overpotential in Isothermal Cells without Transference

SIGNIFICANCE OF EA DETERMINED AT CONTROLLED OVERPOTENTIAL IN ISOTHERMAL CELLS WITHOUT TRANSFERENCE 

It follows from Table 5 that EAs determined in the simplest cell in an isothermal regime, with overpotential as the experimental substitute for A0 at WE, that is. 

As stated earlier (see Section II. 1), zero overpotential rj = 0) is assumed as the electrical reference point when Eqs. (17) and (25) are derived. For reversible electrode reactions, the equilibrium state it] = 0) is experimentally accessible, constant, and reproducible, and, in accordance with the definition of overpotential given by Eq. (13), it is formally temperature independent. An electrical reference point i/ = 0 is easily 

One of the principal requirements when the effect of temperature on the rate of electrode reactions is evaluated is to keep A0we = const at any temperature within the range studied [see Eq. (7)]. Is this requirement really satisfied when / = 0 is selected as the electrical reference point and the overpotential is the experimental substitute for A(A0) in the WE-RE cell  

an w-EAZOP, as well as any w-EACOP, depends on A0 of the reaction studied at the WE. However, the temperature independence of tj = 0 does not imply a temperature-independent equilibrium state of the reaction considered, that is, dA /dT = 0. Any compilation of temperature coefficients of standard electrode potentials clearly indicates that the equilibrium state of electrode reactions is generally affected by temperature, which means that electrode reactions are characterized by A A 0. 

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