ANS:B - Electrodylsis is used in the manufacture of NaOH.

Electrolysis is used in the manufacture of NaOH (sodium hydroxide) through a process known as the chloralkali process. This process involves the electrolysis of a sodium chloride (NaCl) solution, commonly known as brine. Here's how the chloralkali process works:

1. Electrolysis Cell: The process takes place in an electrolysis cell, which consists of a cathode (negative electrode) and an anode (positive electrode) immersed in a brine solution.
2. Ion Migration: When an electric current is passed through the brine solution, it undergoes electrolysis. The sodium chloride (NaCl) dissociates into its constituent ions: sodium ions (Na⁺) and chloride ions (Cl⁻).
3. Ion Discharge: At the cathode, sodium ions (Na⁺) migrate towards the cathode and gain electrons to form sodium metal (Na) according to the half-reaction: 2Na++2e−→2Na2Na++2e−→2Na
4. Chlorine Production: At the anode, chloride ions (Cl⁻) migrate towards the anode and lose electrons to form chlorine gas (Cl₂) according to the half-reaction: 2Cl−→Cl2+2e−2Cl−→Cl2​+2e−
5. Hydrogen Production: Additionally, hydrogen gas (H₂) is produced at the cathode due to the reduction of water molecules present in the brine solution: 2H2O+2e−→H2+2OH−2H2​O+2e−→H2​+2OH−
6. Formation of NaOH: Meanwhile, hydroxide ions (OH⁻) are generated at the cathode due to the reduction of water molecules. These hydroxide ions react with the sodium ions produced at the cathode to form sodium hydroxide (NaOH): Na++OH−→NaOHNa++OH−→NaOH
7. Separation and Collection: The sodium hydroxide solution (NaOH) is then separated from the brine solution and collected.