Solution:Concept- Electrolysis is defined as the process of breaking down ionic compounds into their elements by passing direct current through the compound in liquid form. Cations are reduced at the cathode and anions are oxidised at the anode.
The anode is connected to the positive terminal of the cell, while the cathode is connected to the negative terminal. We know that is made up of the ions and . This molten substance will be broken down into positively charged sodium ions and negatively charged chloride ions during electrolysis. The sodium ion will travel towards the negatively charged cathode, while the chloride ion will move towards the positively charged anode. These ions are oxidised and reduced separately. will be oxidised to by losing an electron since the anode aids oxidation. will be reduced to by accepting electrons since the cathode aids reduction. As a result, chlorine gas is generated at the anode.
Hence, the correct answer is 4.