Question

Write briefly about the methods of electrolysis of sodium chloride

Answer 1

Electrolysis➫ The producing of chemical changes by passage of an electric current through an electrolyte.

>The three methods of electrolysis of sodium chloride are:

•Dilute aqueous sodium chloride solution produces hydrogen at the cathode & oxygen at the anode.

•Concentrated aqueous sodium chloride solution produces hydrogen at the cathode & chlorine at the anode.

• Aqueous solutions of intermediate concentrations may produce both chlorine & oxygen at the anode.

> Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell.

Answer 2

1. when an electric current is passed through very diluted solutions of sodium chloride (dissolved 2g salt in 500ml pure water) it is electrolysed and hydrogen gas is liberated at the cathode and oxygen gas is liberated at the anode.

2. when an electric current is passed through a saturated solution of sodium chloride it is electrolysed and hydrogen gas is liberated at the cathode and chloride gas is liberated at the anode.