Science — AI-generated practice question

Chlor-alkali Process:

When electricity is passed through an aqueous solution of sodium chloride (brine), it decomposes. This process is called the chlor-alkali process (chlor → chlorine; alkali → sodium hydroxide).

Balanced chemical equation:

$$2\text{NaCl(aq)} + 2\text{H}_2\text{O(l)} \rightarrow 2\text{NaOH(aq)} + \text{Cl}_2\text{(g)} + \text{H}_2\text{(g)}$$

Products formed and their uses:

| Product | Where formed | One important use |
|---|---|---|
| Chlorine (Cl₂) | At the anode | Used to manufacture bleaching powder; also for disinfecting drinking water |
| Hydrogen (H₂) | At the cathode | Used as fuel / in making margarine |
| Sodium hydroxide (NaOH) | Near the cathode | Used in making soap and paper industries |

Source: Chapter 2, Section 2.4.3 — Chemicals from Common Salt

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• The equation must be balanced and include state symbols — examiners deduct marks if either is missing.
• Name all three products (Cl₂, H₂, NaOH) and state where each is released (anode/cathode) — this is a common detail examiners check.
• Give one distinct, correct use per product; vague answers like "used in industry" score poorly.
• The name "chlor-alkali" should be explained briefly (chlor = chlorine, alkali = NaOH) as it is directly asked in many variants of this question.