A voltaic cell prepared using aluminum and nickel has the following cell notation. Al(s) | Al³⁺(aq) || Ni²⁺(aq) | Ni(s)
Which of the following represents the correctly balanced spontaneous reaction equation for the cell?

Question

Quizplus · Accepted Answer

The correct balanced reaction equation for the given cell notation can be determined by identifying the oxidation and reduction half-reactions. In this case, the aluminum electrode is the anode and undergoes oxidation while the nickel electrode is the cathode and undergoes reduction. The half-reactions are:

Al(s) → Al3+(aq) + 3e- (oxidation)
Ni2+(aq) + 2e- → Ni(s) (reduction)

Multiplying the oxidation half-reaction by 2 and the reduction half-reaction by 3 (to balance the number of electrons transferred) gives:

2Al(s) → 2Al3+(aq) + 6e-
3Ni2+(aq) + 6e- → 3Ni(s)

Adding these two half-reactions together gives the overall reaction:

3Ni2+(aq) + 2Al(s) → 2Al3+(aq) + 3Ni(s)

which corresponds to choice B.

A Voltaic Cell Prepared Using Aluminum and Nickel Has the Following