Consider the overall reaction taking place in a voltaic cell.

\[{\text{A}}{{\text{g}}_{\text{2}}}{\text{O(s)}} + {\text{Zn(s)}} + {{\text{H}}_{\text{2}}}{\text{O(l)}} \to {\text{2Ag(s)}} + {\text{Zn(OH}}{{\text{)}}_{\text{2}}}{\text{(s)}}\]

What is the role of zinc in the cell?

A.     The positive electrode and the oxidizing agent.

B.     The positive electrode and the reducing agent.

C.     The negative electrode and the oxidizing agent.

D.     The negative electrode and the reducing agent.

D

One G2 comment suggested that it would have been better if other examples were used in this voltaic cell, instead of the salts chosen. Although a valid comment, candidates simply had to realise that zinc changes its oxidation number from 0 to \( + 2\) and hence is oxidized, so therefore must be the negative electrode and the reducing agent. The question itself was answered correctly by only 39.27% of candidates.