If E° for copper electrode is + 0.34 V how will you calculate its emf value when the solution in contact with it is 0.1 M in copper ions? How does emf for copper electrode change when concentration of Cu2+ ions in the solution is decreased?
The emf of an electrode when dipped in different concentrated solution is given by Nernst equation.
Substituting the given values, we get
When concentration of Cu2+ ion in the solution decreases the emf of the electrode decreases. In this case it has decreased from 0.34 V to 0.3105 V.