Note 546 — Chapter XIV · OXIDATION AND REDUCTION REACTIONS. I
Reading edition
This ratio need not be 1017, since we have two solutions combined with each other and the total potential will be expressed by:
ε = ε1 − ε2 = 0.058 (log 1017 × [Fe3+]1 − log 1017 × [Fe3+]2 )
[Fe2+]1 [Fe2+]2
= 0.058 log [Fe3+]1 × [Fe2+]2 .
[Fe2+]1 × [Fe3+]2
Equilibrium is reached when the total potential is 0. Then
[Fe3+]1 × [Fe2+]2 = 1
[Fe2+]1 × [Fe3+]2
and
[Fe2+]1 = [Fe2+]2 .
[Fe3+]1 [Fe3+]2