Question

An electrolytic cell is set up using two copper electrodes and an aqueous solution of copper (II) sulphate given below:

Name the ion discharged at the cathode.

• A. Cu²⁺
• B. SO₄^2-
• C. OH^-
• D. H⁺

Answer 1

The correct option is A

Cu²⁺

The ions present in the aqueous copper sulphate are $C{u}^{2+},H^{+},S{O}_4^{2-}andO{H}^{-}$. Both $C{u}^{2+}and{H}^{+}$​ ions migrate to the cathode. The copper ions are below hydrogen ions in the activity series, thus, copper ions discharge in preference to $H^{+}$ ions to form neutral copper atoms.

$C{u}^{2+}+2e^{-}\to Cu$

The reddish brown copper is deposited at the cathode.