Question

How do you write anode and cathode reactions?

Answer 1

The anode is the cell where oxidation takes place and the cathode is the cell where reduction takes place.

1. Oxidation is the removal of electron and addition of Oxygen atom during the redox reaction.
2. Reduction is the addition of electron and removal of Oxygen atom during the redox reaction.
3. The standard cathode and anode reaction for Daniel cell can be written as:

Anode: $\mathrm{Zn}\left(\mathrm{s}\right)\underset{}{\overset{}{\to }}{\mathrm{Zn}}^{+2}(\mathrm{aq}.)+2{\mathrm{e}}^{-}$

Cathode: ${\mathrm{Cu}}^{+2}(\mathrm{aq}.)+2{\mathrm{e}}^{-}\underset{}{\overset{}{\to }}\mathrm{Cu}\left(\mathrm{s}\right)$

For full cell reaction, ${\mathrm{CuSO}}_4(\mathrm{aq}.)+\mathrm{Zn}\left(\mathrm{s}\right)\underset{}{\overset{}{\to }}{\mathrm{ZnSO}}_4(\mathrm{aq}.)+\mathrm{Cu}\left(\mathrm{s}\right)$

Hence, from the above reaction, the anode and cathode reactions can be visualized.