Science (086) — AI-generated practice question

Yes, I agree with the statement.

Justification:
In a double displacement reaction, ions are exchanged between two compounds. A precipitation reaction is a type of double displacement reaction where one product is insoluble (precipitate). However, double displacement reactions can also produce water (neutralisation) or a gas instead of a precipitate.

Example of a double displacement reaction WITHOUT a precipitate:

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

Here, OH⁻ and Cl⁻ ions are exchanged (double displacement), but no precipitate is formed — only water and sodium chloride in solution are produced.

Source: Chapter 1, Section 1.2.4 Double Displacement Reaction

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• The examiner awards marks for: (1) agreeing and stating the logic (all precipitation reactions involve ion exchange = double displacement), (2) explaining that double displacement reactions are broader (can produce water/gas too), and (3) a correct example with equation.
• The neutralisation reaction NaOH + HCl is the simplest and most reliable example to use here since it appears in the chapter's exercises.
• Do not write a neutralisation reaction as a precipitation reaction — they are distinct subtypes of double displacement.