Group members: Jamoy Mullings, Shanelle Smith, Shawn-de Bernard, Shamoy Pusey

Principle and Outline of Sodium’s Extraction

Down's Process is based on the electrolysis of fused NaCl ( sodium chloride).

Down's cell consists of a rectangular container of steel.

Inside of the tank is lined with firebricks.

In the Down's Cell a circular iron cathode surrounds the carbon anode and the products of the electrolysis are separated by a steel mesh or gauze to prevent them coming into contact and reforming sodium chloride. 

At the carbon anode chloride ions are oxidized to form chlorine gas.

 At the iron cathode sodium ions are reduced to sodium atoms. 

Formula: Anode: (positive carbon electrode)2Cl-(l) → Cl2(g) + 2e

Cathode: (negative iron electrode)Na+

(l) + e → Na(l)

2Cl-(l) + 2Na+(l) → Cl2(g) + 2Na(l)

Manufacture of Sodium Hydroxide

Electrolysis of concentrated sodium chloride solutions (brine) produces chlorine gas, hydrogen gas and aqueous sodium hydroxide.

2NaCl(aq) + 2H2O(l) -----> H2(g) + Cl2(g) + 2NaOH(aq)

The electrolysis of sodium chloride to produce sodium hydroxide and chlorine can be carried out in 3 types of electrolytic cells - mercury, diaphragm and membrane cells

Uses of sodium hydroxide

domestic oven and drain cleaner

Manufacture of Soap and detergent products

removal of sulphur dioxide and hydrogen sulphide in petroleum refining

pulp and paper production

Uses of Sodium

Sodium vapour street lights

manufacture of zirconium (Zr), titanium (Ti), sodium cyanide (NaCN), sodium peroxide (Na2O2), sodium hydride (NaH)