Question

What is Brine Solution?

Answer 1

Brine solution:

• Brine solution is a highly concentrated solution of Sodium Chloride ($\mathrm{NaCl}$) or common salt.
• It also occurs naturally in salt lakes or seawater as well.
• Natural brine is used for commercial purposes to obtain common salt and other salts like Sulphates and Chlorides of Potassium and Magnesium or potash ($\mathrm{KCl},{\mathrm{MgSO}}_4,{\mathrm{K}}_2{\mathrm{SO}}_4,{\mathrm{MgCl}}_2$).
• It is obtained as evaporite deposits from salt domes (a condition where salt intrudes over underlying rocks)

Electrolysis of brine solution:

• When electric current is passes through brine solution, it produces Hydrogen gas (${\mathrm{H}}_2$) evolved at the cathode and Chlorine gas (${\mathrm{Cl}}_2$) at the anode (along with sodium Hydroxide ($\mathrm{NaOH}$) in dissolved form)

$$\begin{gathered} \mathrm{Cathode}:2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2\left(\mathrm{g}\right)\uparrow \\ \mathrm{Anode}:2{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)\to {\mathrm{Cl}}_2\left(\mathrm{aq}\right)\uparrow +2{\mathrm{e}}^{-} \end{gathered}$$