Hello! Electrolysis question. :)

When electrolysing aqueous copper (II) sulfate using copper electrodes, why does the concentration of the copper (II) sulfate remain constant during the experiment?

Thank you!

Question

Hello! Electrolysis question. :)

When electrolysing aqueous copper (II) sulfate using copper electrodes, why does the concentration of the copper (II) sulfate remain constant during the experiment? 

Thank you!

anonymous · Answer

it just acts as a conductor.. there is no "lysis" happening.
$$CuSO_4\longrightarrow Cu^{2+}+SO_4^{2-}\qquad\text{in the electrolyte}\
Cu\longrightarrow Cu^{2+}+2e^-\qquad\text{from electrode}$$
the net reaction has replacement of $Cu^{2+}$ in the electrolyte by the one on the electrode. Hence, there is no loss/gain