Chapter 18, Problem 18.98QE

Interpretation Introduction

Interpretation:

The potential of the half reaction has to be calculated.

${\text{Fe}}^{3+}{\text{+ e}}^{\text{-}}\to {\text{ Fe}}^{+2}$

Concept Introduction:

According to the Nernst equation, the cell potentials are related to concentrations of reactants and products and to temperature as follows.

  ${\text{E = E}}^{\text{0}}\text{-}\left(\frac{\text{RT}}{\text{nF}}\right)\text{lnQ}$

At 298K the Nernst equation is as follows:

  ${\text{E = E}}^{\text{0}}\text{ - }\frac{\text{0}\text{.0591}}{\text{n}}\text{ logQ at 298 K}$

The relation between standard cell potential and equilibrium constant is as follows.

  $\text{log}\text{K = }\frac{{\text{nE}}^{\text{0}}}{\text{0}\text{.0591}}\text{ at 298K}$