Q1. [3] medium thorough-understanding
In the chlor-alkali process, electrolysis of brine produces products at both electrodes. Name the products released at each electrode, give their uses, and explain why the process is called 'chlor-alkali'.
Generated by claude-sonnet-4-6 · 2026-06-26 01:04 · grounding rag
Model Answer
Chlor-alkali process involves electrolysis of brine (NaCl solution):
- At cathode: Hydrogen gas (H₂) is released. Used as fuel and in margarine production.
- At anode: Chlorine gas (Cl₂) is released. Used in water treatment (disinfection) and PVC manufacturing.
- In solution: Sodium hydroxide (NaOH) is formed. Used in degreasing, soap making, and paper industry.
Why called 'chlor-alkali': The process produces chlorine (chlor) and sodium hydroxide — an alkali (alkali) — hence the name chlor-alkali process.
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Explanation
- Examiners expect you to name all three products (Cl₂, H₂, NaOH), locate them correctly (anode/cathode/solution), give at least one use each, and explain the name derivation.
- "Chlor" = chlorine; "alkali" = NaOH. That two-part etymology directly explains the name — don't skip it.
- This topic is from Chapter 2 (Acids, Bases and Salts), specifically the section on salts and their uses. It is a frequent 3-mark question.