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Question
Starting with sodium chloride how would you proceed to prepare sodium metal.
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Solution
Sodium can be extracted from sodium chloride by Downs process.
This process involves the electrolysis of fused NaCl (40%) and CaCl2 (60 %) at a temperature of 1123 K in Downs cell.
Steel is the cathode and a block of graphite acts as the anode. Metallic Na and Ca are formed at cathode. Molten sodium is taken out of the cell and collected over kerosene.
\[\ce{NaCl ->[Electrolysis] Na+ + Cl-}\]
Molten
At Cathode : \[\ce{Na^+ + e^- -> Na}\]
At Anode : \[\ce{Cl- + e- -> Cl}\]
\[\ce{Cl + Cl -> Cl_2}\]
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