An Example

Figure 34-1: Example Battery

Writing out the the equilibrium equations between each of the phases:

At I/II

$$\input{equations/ec-1-2}$$ (34-13)

At II/III

$$\input{equations/ec-2-3}$$ (34-14)

At III/IV

$$\input{equations/ec-3-4}$$ (34-15)

At Electrodes

$$\input{equations/27-6A}$$ (34-16)

or²

$$\input{equations/27-6B}$$ (34-17)

Combining all the equilibrium equations and solving:

$$\input{equations/27-6C}$$ (34-18)

If the membrane is perfect: $\mu^{\mbox{II}}_{\mbox{SO}_4^{--}} = \mu^{\mbox{III}}_{\mbox{SO}_4^{--}}$, then:

$$\input{equations/nernst}$$ (34-19)

Which is known as the Nernst Equation.