Starting with sodium chloride how would you proceed to prepare (i) sodium metal (ii) sodium hydroxide (iii) sodium peroxide (iv) sodium carbonate ?

Explanation

a. Sodium metal is manufactures by electrolysis of a fused mixture of NaCI `(40%)` and `CaCI_(2)` `(60%)` in Down's cell at 873 K using iron cathode and graphite anode. Na is liberated at the cathode while `CI_(2)` is evolved at the anode.
At cathode: `Na_(("melt"))^(o+)+e^(Θ)rarr Na_((1))`
At anode: `2CI_(("melt"))^(Θ)rarr CI_(2(g))+2e^(Θ)`
ii. Sodium hydroxide is manufactured by electrolysis of an aqueous solution of NaCI (brine) in Caster-Kellner cell using the mercury cathode and the carbon anode. Sodium which is discharged at the cathode combines with mercury to form sodium amalgam. `CI_(2)` gas is evolved at the anode.
At cathode: `Na^(o+)+e^(Θ)rarr underset("Sodium")(Na)`
`2Na+x x Hg rarr underset("Sodium amalgam")(Na_(2)Hg_(x))`
At anode: `2CI^(Θ)rarr CI_(2)+2e^(Θ)`
The sodium amalgam thus obtained is treated with water to form sodium hydroxide and hydrogen gas.
`Na_(2)Hg_(x)+2H_(2)O_(2)rarr 2NaOH+xHg+H_(2)`
c. Sodium peroxide is obtained by heating oxide reacts with more `O_(2)` to form `Na_(2)O`
`4Na+O_(2)rarr 2Na_(2)O`
`4Na_(2)O+O_(2)rarr 2Na_(2)O_(2)`