Tuesday, October 7, 2008

electrolysis of sodium chloride

Sodium hydroxide, chlorine and hydrogen are produced from natural deposits of sodium chloride (rocksalt). This is the basis of the chloralkali industry. Electrolysis of brine (salt solution) produces 1 tonne of chlorine at the same time as 1.13 tonnes of sodium hydroxide and 0.028 tonnes of hydrogen. There are many different processes used in the electrolysis of brine. An aqueous solution contains the following ions: Na+, Cl-, H+ and OH-.

at anode

2Cl- Cl2 + +2e-

At cathode:
2H+ + 2e- H2

* The remaining solution contains NaOH

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chemistry notes / igcse-gcse- Olevel