Chloroalkali Industry
Compare simple brine electrolysis with membrane cells producing chlorine, hydrogen, and sodium hydroxide
Simple electrolysis of brine
Cathode (-)
Anode (+)
DC POWER
12.0 V
HKDSE Tip
- Ion migration:Cations (Na⁺, H⁺) move to the cathode; anions (Cl⁻, OH⁻) move to the anode.
- Solution change:As H⁺ is discharged, OH⁻ concentration increases and the solution becomes alkaline (NaOH forms).
- Anode gas test:Use moist blue litmus paper (not dry) near the anode.