Question

State the chemical reactions that take place during the electrolysis of sodium chloride.
[2 Marks]

Answer 1

Sodium chloride is heated to obtain the molten salt. The molten salt forms the ions as follows:

$\text{NaCl(l)}\to {\text{Na}}^{+}\left(l\right)+{\text{Cl}}^{-}\left(l\right)$

The negatively charged chloride ions are attracted towards the positive electrode, anode. The reaction that occurs at anode is:

${\text{2Cl}}^{-}\left(l\right)\to {\text{Cl}}_2\left(g\right)+{\text{2e}}^{-}$
[1 Mark]

The positively charged sodium ions move towards the negative electrode, cathode, and accept one electron each from the electrode and form the sodium metal. The reaction that occurs at the cathode is:

${\text{2Na}}^{+}\left(l\right)+{\text{2e}}^{-}\to \text{2Na}\left(s\right)$
<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> [1 Mark]