Starting from sodium chloride, how will you proceed to prepare (i) sodium metal (ii) sodium hydrxide (iii) sodium peroxide (iv) sodium carbonate.

Explanation

(i) Sodium metal is manufactured by electrolysis of a fused mixture of NaCl (40%) and CaCl, (60%) in Down cell at 873K using graphite anode and iron cathode. Sodium is liberated at the anode while `Cl_(2)` is evolved at cathode
At cathode : `Na^(+) ("melt")+e^(-) to Na(l) `
`2Cl^(-)("melt") to Cl_2 + 2e^(-)`
(ii) Sodium hydroxide is manufactured by electrolysis of sodium chloride (brine) in Castner Kellner cell, using carbon anode and mercury cathode. Sodium metal discharged at the cathode combines with mercury to form sodium amalgam while `Cl_2` gas is evolved at the anode.
Cathode : `Na^(+) + e^(-) to Na `
`2Na + Hg to NaHg` (amalgam)
`2Cl^(-) to Cl_2 + 2e^(-)`
The amalgam reacts with water to give `NaOH ` and `H_2` gas is evolved.
`2NaHg+2H_2O to 2NaOH + 2Hg + H_2`
(iii) Sodium peroxide is manufactured by heating sodium in excess of oxygen. The initially formed sodium oxide reacts with more oxygen to form `Na_2O_2`
`2Na + (1)/(2) O_2 to Na_2O`
`2Na_2 O + O_2 to 2Na_2O_2`
(iv) Sodium carbonate is obtained by Solvay process .