Lawrie Ryan and Roger Norris Solutions for Chapter: Electrochemistry, Exercise 5: Questions

Explain why cations move towards the cathode during electrolysis.

When lead iodide, ${\mathrm{PbI}}_2$ is electrolysed, the following reactions occur:
${\mathrm{Pb}}^{2+} + 2{\mathrm{e}}^{-} \to \mathrm{Pb}$ and
$2{\mathrm{I}}^{-} \to {\mathrm{I}}_2 +2{\mathrm{e}}^{-}$

Which of these equations describes the reaction at the cathode? Explain your answer.

State the oxidation number change of each iodide ion in the reaction: $2{\mathrm{I}}^{-} \to {\mathrm{I}}_2 + 2{\mathrm{e}}^{-}$