Question

Which reaction occurs at the cathode of a galvanic cell that has an aluminum electrode in an electrolyte with aluminum ions and a copper electrode in an electrolyte with copper ions? The reduction potential for the reduction of Cu₂+ = 0.34 V. The reduction potential for the reduction of Al₃+ = -1.68.

A. Cu₂+(aq) + 2e- -> Cu(s)
B. Cu(s) -> Cu₂+(aq) + 2e-
C. Al₃+(aq) + 3e- -> Al(s)
D. Al(s) -> Al₃+(aq) + 3e-

Answer 1

At the cathode of a galvanic cell with aluminum and copper electrodes, the reaction Cu2+(aq) + 2e- -> Cu(s) occurs because copper has a more positive reduction potential than aluminum.

Step-by-step explanation:

The question is asking which reaction occurs at the cathode of a galvanic cell with aluminum and copper electrodes in their respective electrolytes.

In a galvanic cell, the cathode is where reduction takes place. The electrode with the more positive reduction potential will undergo reduction. Since reduction potentials are given as Cu2+ = 0.34 V and Al3+ = -1.68 V, the copper reaction has the more positive reduction potential and will be reduced at the cathode.

The correct reaction that occurs at the cathode thus is:

Cu2+(aq) + 2e- -> Cu(s)

This corresponds to option A and signifies the reduction of Cu2+ ions to copper metal at the cathode of the galvanic cell.