Chlorine Gas

Brief Overview
Chlorine is a pale yellow-green gas which has atomic number 17. It is used in household products and generally used in industry. Chlorine is a reactive and also strong oxidizing agent. It has various properties, such as pungent, irritating odor, non-flammable, but will react explosively with other chemicals like ammonia and turpentine. In water treatment, chlorine is generally used as a disinfectant to kill harmful bacteria.

Manufacturing Process
Chlorine can be produced by the Chloralkali process which is the electrolysis of a sodium chloride solution. The co-products of the reaction are caustic soda (sodium hydroxide) and hydrogen gas (H2). Chlorine can also be produced by electrolyzing a potassium chloride solution, which produces hydrogen and caustic potash as co-products (potassium hydroxide). There are three industrial methods for extracting chlorine from chloride solutions using electrolysis, all of which follow the equations below:
For cathode: 2 H+ (aq) + 2 e− → H2 (g)
For anode: 2 Cl− (aq) → Cl2 (g) + 2 e−
The overall process can be written below:
2 NaCl + 2 H2O → Cl2 + H2 + 2 NaOH