Electrolysis of active metals like Na, K, Al is not carried out by using aqueous solution of their chloride.

1. Decomposition of an electrolyte by passage of electric current through it is called as electrolysis.
2. The metals extracted by electrolysis by passing electric current are very pure, they do not contain impurities.
3. If we carry out electrolysis of aqueous solution of sodium chloride, as soon as sodium metal is produced, it will react with water present in aqueous solution to form sodium hydroxide. Thus we get sodium hydroxide instead of sodium metal.
So, sodium, potassium, calcium metals are obtained by electrolysis of molten chloride.