Standard Electrode Potentials and Electrochemical Series

Explain why ${\mathrm{Cu}}^{+}$ disproportionates in solution.

Why is it possible to obtain zinc by electrolysis of an aqueous solution even though the electrode potentials would suggest that the water should decompose first?

How is it possible to preferentially deposit metals electrolytically, like $\mathrm{Cu}, \mathrm{Ni}$ and $\mathrm{Zn}$ from a solution containing all three?

Explain the recovery of copper from a solution using scrap iron.

What are the standard electrode potentials, and how are they related to the electrochemical series?