Question

Consider a galvanic cell in which Al3 is reduced to elemental aluminum, and magnesium metal is oxidized to Mg2 . Write the balanced half-cell reactions that take place at the cathode and at the anode.

Consider a galvanic cell in which Al^3 is reduced to elemental aluminum, and magnesium metal is oxidized to Mg2 . Write the balanced half-cell reactions that take place at the cathode and at the anode. Half - cell reaction at the cathode Half - cell reaction at the anode

Answer 1

Concepts and reason

Galvanic cell consists of two different electrodes called as anode and cathode. Oxidation takes place at anode and reduction takes place at cathode.

First observe the cations and anions that present in the electrolytes. Write the half-cell reactions based on the oxidation and reduction reactions of the ions.

Fundamentals

In the electrochemical cell cathode is a negative electrode, cations can move towards it and undergoes reduction; Anode is a negative electrode, anions can move towards it and undergoes oxidation.

In the galvanic cell, the cations are ${\rm{A}}{{\rm{l}}^{3 + }}$ and ${\rm{M}}{{\rm{g}}^{{\rm{2 + }}}}$ .

The galvanic cell reaction is as follows:

${\rm{Mg}}\left( {\rm{s}} \right){\rm{ }}\left| {{\rm{ M}}{{\rm{g}}^{{\rm{2 + }}}}{\rm{ }}} \right|\left| {{\rm{ A}}{{\rm{l}}^{{\rm{3 + }}}}{\rm{ }}} \right|{\rm{ Al}}\left( {\rm{s}} \right)$

The balanced half-cell reactions are as follows:

At cathode:

${\rm{2A}}{{\rm{l}}^{3 + }}{\rm{ + 6}}{{\rm{e}}^ - } \to 2{\rm{Al}}$

At anode:

${\rm{3Mg}} \to {\rm{3M}}{{\rm{g}}^{2 + }}{\rm{ + 6}}{{\rm{e}}^ - }$

Ans:

The balanced half-cell reactions are as follows:

At cathode:

${\rm{2A}}{{\rm{l}}^{3 + }}{\rm{ + 6}}{{\rm{e}}^ - } \to 2{\rm{Al}}$

At anode:

${\rm{3Mg}} \to {\rm{3M}}{{\rm{g}}^{2 + }}{\rm{ + 6}}{{\rm{e}}^ - }$