Q1. [3] deep thorough-understanding
Consider the reaction: Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s). (i) Identify the type(s) of chemical reaction this represents, giving a reason for each type you name. (ii) In terms of oxidation and reduction, identify which species is oxidised and which is reduced, and state how you determined this.
Generated by claude-sonnet-4-6 · 2026-06-26 00:55 · grounding rag
Model Answer
(i) Types of reaction:
- Displacement reaction: Fe displaces Cu from CuSO₄ because iron is more reactive than copper, so a more reactive metal displaces a less reactive metal from its salt solution.
- Redox reaction: Both oxidation and reduction occur simultaneously in this reaction.
(ii) Oxidation and Reduction:
- Fe is oxidised: It loses electrons/gains no oxygen, going from Fe (0) to Fe²⁺ in FeSO₄. (Iron gains no oxygen here but is oxidised as a species.)
- Cu²⁺ is reduced: Copper ions in CuSO₄ gain electrons to form Cu(s), i.e., Cu²⁺ → Cu(0) — loss of combined state/gain of electrons.
This is determined by tracking changes in the state of the elements: Fe becomes part of a compound (oxidised) and Cu²⁺ becomes free copper (reduced).
Source: Chapter 1, Section 1.2.5 Oxidation and Reduction; What you have learnt, Chapter 1 & 3
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Explanation
- Examiners expect two reaction types named with reasons: displacement (reactivity basis) and redox (simultaneous oxidation + reduction).
- For Part (ii), at Class 10 level, "oxidised = loses electrons / forms compound" and "reduced = gains electrons / becomes free element" is sufficient. You may also use gain/loss of oxygen language if preferred, but electron transfer is cleaner here since no oxygen transfer occurs directly.
- Always state how you determined it — that's explicitly asked and carries marks.