Write answers to the following

Write briefly about the three methods of electrolysis of sodium chloride.

(i)When an electric current is passed through a saturated solution of sodium chloride (brine) it is electrolysed and hydrogen gas is released at the cathode while chlorine gas is released at the anode. This method is used for production of chlorine gas. In this method an important basic compound NaOH is formed in the cell.

(ii) When salt is heated to a high temperature (about

800◦C) it melts. This is called the fused state of the salt.

(iii) When fused salt is electrolysed, chlorine gas is

released at the anode and liquid sodium metal, at the cathode