A voltaic cell is made by connecting a copper half-cell, \({\text{Cu(s)}}\left| {{\text{C}}{{\text{u}}^{2 + }}{\text{(aq)}}} \right.\), to an iron half-cell \({\text{Fe(s)}}\left| {{\text{F}}{{\text{e}}^{2 + }}{\text{(aq)}}} \right.\).

Which combination correctly identifies the positive electrode and the species being oxidized?

A

Questions such as this have been set in the past and we would expect a chemist at this level to have a rudimentary knowledge of metals in an activity series, particularly those as far apart as iron and copper. It was disappointing that less than 50% got this right.