Chapter 18, Problem 18.22P

Interpretation Introduction

Interpretation:

The equilibrium constant for the given reaction should be determined.

Concept introduction:

• Nernst Equation: Nernst Equation gives the quantitative relationship between the concentration of ions, temperature and electrode potential or cell potential.
The equation for Nernst equation is as follow:

  ${\text{E}}_{\text{cell}}{\text{=E}}^{\text{0}}{}_{\text{cell}}-\frac{0.0591}{\text{n}}\log \frac{{\left[\text{X}\right]}^{\text{x}}{\left[\text{Y}\right]}^{\text{y}}}{{\left[\text{A}\right]}^{\text{a}}{\left[\text{B}\right]}^{\text{b}}}$

Where n is the number of electrons involved in the cell reaction.


• At equilibrium, E_cell=0 , therefore, the Nernst equation is

  ${\text{E}}^{\text{0}}{}_{\text{cell}}\text{=}\frac{\text{0}\text{.0591}}{\text{n}}{\text{logK}}_{\text{c}}$
• Cell potential: The potential difference between two half cell which constitute an electrochemical cell when no current is flowing through it is called cell potential or EMF of the cell.

  ${\text{E}}^{\text{0}}{}_{\text{cell}}{\text{=E}}^{\text{0}}{}_{\text{cathode}}-{\text{E}}^{\text{0}}{}_{\text{anode}}$