Science — AI-generated practice question

Displacement Reaction: When a more reactive element displaces a less reactive element from its compound.

Example:
$$\text{Fe}(s) + \text{CuSO}_4(aq) \rightarrow \text{FeSO}_4(aq) + \text{Cu}(s)$$
(Iron displaces copper from copper sulphate solution — Displacement Reaction)

Double Displacement Reaction: Two different ions are exchanged between the reactants to form two new compounds.

Example:
$$\text{Na}_2\text{SO}_4(aq) + \text{BaCl}_2(aq) \rightarrow \text{BaSO}_4(s) + 2\text{NaCl}(aq)$$
(Sulphate and chloride ions exchange between reactants — Double Displacement Reaction)

Source: Chapter 1, Section 1.2.4

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• Examiners expect a clear one-line definition of each type (1 mark each), plus one correct balanced equation for each (½ mark each) and correct identification of the type (mentioned in the equation line).
• The key distinction to highlight: in displacement, one element replaces another; in double displacement, two ions/groups are exchanged between two compounds.
• Always include state symbols (s), (aq) etc. where possible — it shows thoroughness without adding length.