Starting with sodium chloride how would you proceed to prepare sodium hydroxide
Sodium hydroxide can be prepared by the electrolysis of sodium chloride. This is called Castner–Kellner process. In this process, the brine solution is electrolysed using a carbon anode and a mercury cathode.
The sodium metal, which is discharged at a cathode, combines with mercury to form an amalgam.
Anode: `Cl -> 1/2 Cl_2 + e^(-)`
Sodium hydroxide is manufactured by electrolysis of an aqueous solution of NaCl (brine) in Castner-Kellner cell.
Na+ + e– —–> Na
2Na + Hg ——->Na – Hg + 2H20
2Na- Hg + 2H20——>2NaOH +H2 +Hg
Cl– – e– ——->Cl
Cl + Cl——–>Cl2