Question

Which one of the following statements is correct for electrolysis of brine solution?

• A. $OH ^{-}$is formed at cathode
• B. $Cl _2$ is formed at cathode
• C. $O _2$ is formed at cathode
• D. $H _2$ is formed at anode

Hint:

In the electrolysis of brine, chloride ions are oxidized at the anode to produce chlorine gas, and water molecules are reduced at the cathode to produce hydrogen gas and hydroxide ions.

Answer 1

The Correct Option is A

Electrolysis of brine solution
$NaCl(aq.)⟶N{a}_{(aq)}^{+}+C{l}_{\text{(aq)}}^{+}$
At anode $:2C{l}_{\text{(aq.)}}^{+}⟶\underset{\text{(Major)}}{C{l}_2(g)+2e^{-}}$
$2H_2{O}_{(\ell )}⟶\underset{\text{Minor}}{O_{2(g)}}+4H_{(aq)}^{+}+4e^{-}$
At Cathode : $2H_2{O}_{(\ell )}+2e^{-}⟶H_{2(g)}\uparrow +2O{H}_{(aq)}^{-}$
$2N{a}^{+}+2O{H}^{-}⟶2NaOH$

So, the correct option is (A): \(OH^−\) is formed at cathode.