Question

Consider a galvanic cell in which Al 3 is reduced to elemental aluminum and magnesium metal is oxidized to Mg 2 . Write the balanced half-cell reactions that take place at the cathode and at the anode.

Answer 1

Answer: The half cell reactions taking place at cathode and anode is written below.

Explanation:

Oxidation reaction occurs at anode and reduction reaction occurs at cathode. Here, magnesium is getting oxidized and aluminium is getting reduced.

The half reactions for the cell is:

Oxidation half reaction (anode):  $Mg(s)\rightarrow Mg^{2+}(aq.)+2e^-$   ( ×  3)

Reduction half reaction (cathode):  $Al^{3+}(aq.)+3e^-\rightarrow Al(s)$     ( ×  2)

Overall cell reaction:  $3Mg(s)+2Al^{3+}(aq.)\rightarrow 3Mg^{2+}(aq.)+2Al(s)$

Hence, the half cell reactions taking place at cathode and anode is written above.