Question

How does concentration effect an electrochemical cell?

Answer 1

Let's consider a Zn-Cu cell:

`Zn(s) + Cu^(2+) rightleftharpoons Zn^(2+) + Cu(s)`

This is in dynamic equilibrium.

If I increase the concentration of `Cu^(2+)`, ceteris paribus, the electrical potential of the cell will increase, due to the `Q` value increasing.

I like to think of this equation, but Le Chatlier's principle may be useful as well:

`E = E^0 - (0.05916)/n*logQ`

If I decrease the concentration of cathode ions, the voltage will decrease.

Hence,

`E propto ([I_(anode)])/([I_(cathode)])`

If I'm wrong correct me!