Answer:
In the electrolysis of brine, the substances produced at the cathode are sodium metal and hydrogen gas.
Explanation:
In the electrolysis of brine (Sodium chloride solution) using carbon as electrode, Chlorine gas is produced in the positive electrode (anode), while hydrogen gas is produced in the negative electrode (cathode).
Again, in the electrolysis of molten sodium chloride, chlorine gas is produced in anode, while sodium metal is produced in the cathode.
Nacl ⇄ Na⁺ + Cl⁻
Case 1: Molten Nacl
Anode(+ve) Product | Cathode (-ve) product
Cl⁻ -----> Cl + e⁻ | Na⁺ + e⁻ ---------> Na
Cl + Cl ------> Cl₂
Case 2: Nacl solution
Anode(+ve) Product | Cathode (-ve) Product
Cl⁻ -----> Cl + e⁻ | H⁺ + e⁻ ---------> H
Cl + Cl ------> Cl₂ | H + H ------------> H₂
Thus, cathodic products of electrolysis of brine are sodium metal and hydrogen gas
