Q1. [1] § 1.1.2 Balanced Chemical Equations § 1.2.1 Combination Reaction § 1.2.4 Double Displacement Reaction
Identify the correct statement about the following reaction :
2H₂S + SO₂ ⟶ 2H₂O + S
- (A) H₂S is oxidising agent and SO₂ is reducing agent.
- (B) H₂S is reduced to sulphur.
- (C) SO₂ is oxidising agent and H₂S is reducing agent.
- (D) SO₂ is oxidised to sulphur.
Previously asked in CBSE board exam
2024 31/2/1 Q6
Generated by claude-sonnet-4-6 · 2026-06-14 10:28 · grounding rag
Model Answer
(C) SO₂ is oxidising agent and H₂S is reducing agent.
In this reaction, S in H₂S goes from −2 to 0 (oxidised), so H₂S is the reducing agent. S in SO₂ goes from +4 to 0 (reduced), so SO₂ is the oxidising agent.
Explanation
- The agent that gets oxidised is the reducing agent (H₂S: sulphur −2 → 0).
- The agent that gets reduced is the oxidising agent (SO₂: sulphur +4 → 0).
- Options A and D reverse these roles; option B wrongly says H₂S is reduced. Always check oxidation states of the same element on both sides to decide who is oxidised/reduced.
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