Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7

FUNDAMENTAL EQUATIONS

O + ne- Û R

 

Nernst equation: E = E° + RT ln [O]
 nF [R]

E = E° ¢ + 0.0591 log [O]
n [R]

E = E° ¢ + RT ln Co
nF CR

 

Randles-Sevcik: ip = 2.69 X 105n3/2AD1/2Cv1/2

The formal reduction potential, E° ¢ , for an electrochemically reversible couple:

E° ¢ = Epa + Epc
2

 

The number of electrons transferred in the electrode reaction can be determined by the separation between the peak potentials:

D Ep = Epa - Epc ~ 0.059
n

The Gibbs Equation:

D G = D H - TD S

D G = nFE

 The reaction center entropy change, D SRC, reflects the magnitude and sign of conformational changes that occur as a function of temperature:

D SRC = Sred° - Sox° = nF [dE° ¢ ] [ dT ]

 

Model Ferricyanide:

 

[FeII(CN)6]3- + e- Û FeIII(CN)6]4-

The reaction mechanism is an EC mechanism (an electrode reaction followed by a chemical reaction that consumes the product of the electrode reactions:

Electrode: Mb(III) + e- Û Mb(II)

Solution: Mb(II) + O2 Û Mb(III)O2

 

The heterogeneous rate constant, k° , is determined by the evaluation of the kinetic parameter y which is related to the peak potential separation: