Practice Problem 7
Write the line notation for the cell shown in the figure below.
The cell is based on the following half-reactions.
|Oxidation:||Zn Zn2+ + 2 e-|
|Reduction:||2 H+ + 2 e- H2|
Since we list the reactants before the products in a half-cell, we write the following line notation for the anode.
The line notation for the cathode has to indicate that H+ ions are reduced to H2 gas on a platinum metal surface. This can be done as follows.
|cathode:||H+(1.0 M)|||||H2(1 atm)|||||Pt|
Since line notation is read in the direction in which electrons flow, we place the notation for the anode before the cathode, as follows.
|Zn|||||Zn2+(1.0 M)||||||H+(1.0 M)|||||H2(1 atm)|||||Pt|