Question

How caustic soda is prepared (write equation).Name the process. ​

Answer 1

Castner-Kellner process

Principle: In the Castner-Kellner method, electrolysis of brine solution is performed in order to obtain sodium hydroxide.

Castner-Kellner cell: It is a steel tank that is rectangular. Ebonite is lined inside the tank. Titanium acts as an anode and a layer of mercury at the bottom of the tank acts as the cathode.

Ionization of brine solution occurs according to the following reaction:

2NaCl→2Na++2Cl−

When the brine solution comes in contact with electric current, ionization takes place. As a result positive and the negative ions move towards the electrodes. Sodium ions get deposited at the mercury cathode forming a sodium amalgam. Chlorine ions move towards the anode and exit the cell from the top.