Question

Write electrode reactions and cell reaction of the cell Al/Al3+//Cu2+/Cu

Answer 1

Explanation :

Electrode reaction : In the cell, the net oxidation and reduction process takes place at their respective electrodes. It is also known as Half-cell reaction.

The given cell is,

$Al/Al^{3+}(aq)//Cu^{2+}(aq)/Cu$

In the cell representation, Oxidation process is shown on left side and reduction on right side.

The Half-cell reaction is represented as:

Oxidation reaction: (Lose of electrons or increase in oxidation number)

$Al\rightarrow Al^{3+}(aq)+3e^-$        .............(1)

Reduction reaction:  (Gain of electrons or decrease in oxidation number)

$Cu^{2+}(aq)+2e^-\rightarrow Cu$       ..............(2)

Cell reaction

For the cell reaction, First balanced the Half-cell reaction.

Now for the balanced reaction, equation (1) multiply by 2 and equation (2) multiply by 3.

Oxidation reaction :         $2Al\rightarrow 2Al^{3+}(aq)+6e^-$

Reduction reaction :        $3Cu^{2+}(aq)+6e^-\rightarrow 3Cu$

Net cell reaction :            $2Al+3Cu^{2+}(aq)\rightarrow 2Al^{3+}(aq)+3Cu$