OVERVIEW
Production of sodium hydroxide (NaOH) through electrolysis of sodium chloride solution. This is a laboratory-scale version of the industrial chloralkali process.
THE REACTION
Overall reaction: 2NaCl + 2H₂O → 2NaOH + H₂ + Cl₂ At cathode: 2H₂O + 2e⁻ → H₂ + 2OH⁻ At anode: 2Cl⁻ → Cl₂ + 2e⁻
PROCESS DETAILS
The chloralkali process produces three useful products simultaneously: sodium hydroxide (lye), hydrogen gas, and chlorine gas. Keeping the products separated is crucial to prevent unwanted side reactions.
A membrane or diaphragm cell design prevents the chlorine from mixing with the hydroxide solution, which would produce sodium hypochlorite (bleach) instead.
APPLICATIONS
- Soap making (saponification)
- pH adjustment
- Cleaning solutions
- Chemical synthesis precursor
- Drain cleaning
SAFETY
Warning: This process produces chlorine gas (toxic) and hydrogen gas (flammable/explosive). Sodium hydroxide is highly caustic and causes severe burns. Proper ventilation, PPE, and safety protocols are essential. This is a hazardous process requiring appropriate training and equipment.