Question

give the process of manufacture of NaOH using Castner-kellner cell
​

Answer 1

NaOH

• Caustic Soda

• electrolysis of aq. NaCl

NaCl + H2O

NaCl — Na(+) + Cl(-)

H2O — H(+) + OH(-)

At cathode 2H(+) + 2é - H2

At anode 2Cl(-) — Cl2 + 2é

But

Cl2 + NaOH — [Hot] — NaCl + NaClO3 + H2O

[Cold] — NaCl + NaClO + H2O

So to resolve this problem

Castner kellner cell is used, in which,

Hg cathode ( Na> H)

At cathode

Na(+) + é — Na— Na-Hg

( Sodium amalgam)

At anode

2Cl(-) — Cl2 + 2é