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Discuss industrial production of sodium hydroxide (NaOH - Caustic Soda) and mention its properties and uses. |
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Answer» Solution :SODIUM hydroxide is generally prepared commercially by the electrolysis of sodium chloride in Castner-Kellner cell. A brine solution is electrolysed using a mercury cathode and a carbon ANODE. Sodium METAL discharged at the cathode combines with mercury to form sodium amalgam. Chlorine gas is evolved at the anode. Cathode : `Na^(+)+e^(-) overset(Hg)to Na` - amalgam Anode : `Cl^(-) to (1)/(2)Cl_(2)+e^(-)` The amalgam is treated with water to give sodium hydroxide and hydrogen gas. 2Na-amalgam `+2H_(2)O to 2NaOH +2Hg+H_(2)` Properties : Sodium hydroxide is a white, translucent solid. It melts at 591K. It is readily soluble in water to give a strong alkaline solution. CRYSTALS of sodium hydroxide are DELIQUESCENT. The sodium hydroxide solution at the surface reacts with the `CO_(2)`in the atmosphere to form `Na_(2)CO_(3)`. |
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