Question

Sketching and labeling a galvanic cell: Design a galvanic cell that uses the redox reaction
`Fe(s) + 2Fe^(3+)(aq.) rarr 3Fe^(2+)(aq.)`
Identify the anode cathode half-reactions and sketch the experimental setup. Label the anode and cathode, indicate the directon of elecron and ion flow, and identify the sign of each elctrode.
Strategy: First sepreate the overall cell reaction into anode (oxidation) and cathode (reduction) half-reactions. Then, set up two half-cells that use half-reactions, and connect the half-cells with a conducating wire and a salt bridge.

Answer 1

In the overall cell reaction, we observe that iron metal `(Fe)` is oxidized to ferrous ions `(Fe^(2+))` while ferric ions `(Fe^(3+))` are reduced to ferrous ions `(Fe^(2+))`. Therefore, the half-cell reactions are
Anode (oxidation) `Fe(s) rarr Fe^(2+)(aq.) + 2overset(bar)e`
Cathode (reducation) `2 xx [Fe^(3+)(aq.) + e^(-) rarr Fe^(2+) (aq.)]`