Page 2 - 3.LESSON NOTES-(CH-2 -SODIUM CHLORIDE)
P. 2
When electricity is passed through an aqueous solution of sodium chloride
(brine), it decomposes to form sodium hydroxide.
This process is called the chlor-alkali process (Electrolysis of Brine).
On passing electricity through Brine, the following reactions takes place-
In the electrolyte-
-
+
+
NaCl + H2O → Na + Cl + H + OH -
At the Cathode-
+
-
H + e → H
2H → H2
At the Anode-
-
-
Cl → Cl + e
2Cl → Cl2
The overall reaction is as follows-
o The process is termed as the chlor-alkali process.
o The term chlor for chlorine and alkali for sodium hydroxide.
o Chlorine gas is given off at the anode,
o Hydrogen gas is given off at the cathode.
o Sodium hydroxide solution is formed near the cathode in the electrolyte.
2
