Chapter 14.7, Problem 12TY

Interpretation Introduction

Interpretation:

The formal potential of the given reaction has to be calculated.

${\text{O}}_{\text{2}}{\text{+4H}}^{\text{+}}{\text{+4e}}^{\text{-}}\stackrel{}{\rightleftharpoons }{\text{2H}}_{\text{2}}\text{O}$

Concept Introduction:

Cell Voltage:

Cell voltage is the difference between cathode potential and anode potential.

${\text{E}}_{\text{cell}}\text{=}{\text{E}}_{\text{+}}\text{-}{\text{E}}_{\text{-}}$

Nernst equation:

In electrochemistry, the standard reduction potentials are related with the temperature and gas constant and standard electrode potentials and concentrations.

${\text{E}}_{\text{cell}}{\text{=E}}^{\text{0}}{}_{\text{cell}}\text{-}\frac{\text{RT}}{\text{nF}}\text{log}\frac{{\left[\text{cathode}\right]}^{\text{n}}}{{\left[\text{anode}\right]}^{\text{n}}}$

For Diprotic system the formal concentration is given by,

$\left[{\text{H}}_{\text{2}}\text{A}\right]\text{=}\frac{{\left[{\text{H}}^{\text{+}}\right]}^{\text{2}}\text{F}}{{\left[{\text{H}}^{\text{+}}\right]}^{\text{2}}\text{+}\left[{\text{H}}^{\text{+}}\right]{\text{K}}_{\text{1}}{\text{+K}}_{\text{1}}{\text{K}}_{\text{2}}}$

Where,

${\text{K}}_{\text{1}}{\text{,K}}_{\text{2}}$ are acid dissociation constants for ${\text{H}}_{\text{2}}\text{A}$