UPSC Civil Services (Mains), Chemistry optional · 2025 · Paper I
Q5(g). Completing five p-block reactions
Question
Complete the following reactions: (i) S₄N₄ + SbCl₅ → (ii) XeF₆ + PtF₅ → (iii) B₂H₆ + NH₃ (120 °C) → (iv) 8KrF₂ + 2Au → (v) XeOF₄ + XeO₃ →
Answer in brief
Products: (i) S₄N₄·SbCl₅ (ii) [XeF₅]⁺[PtF₆]⁻ (iii) [BH₂(NH₃)₂]⁺[BH₄]⁻ (iv) [KrF]⁺[AuF₆]⁻ (v) XeO₂F₂.
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Coverssulfur nitride S4N4xenon fluoridesdiborane ammoniakrypton difluorideXeO2F2unsymmetrical cleavage
All parts of Question 5
- 5(a) Activation energy from two rate constants5 marks
- 5(b) Light absorbed by a dye solution5 marks
- 5(c) Surface area of charcoal from a nitrogen monolayer5 marks
- 5(d) Showing that a decomposition is first order5 marks
- 5(e) Structure of [4Fe–4S] ferredoxin5 marks
- 5(f) Which complex has the larger Δₒ10 marks
- 5(g) Completing five p-block reactions10 marks
- 5(h) Magnetic moment: spin only in the d-block, not in the f-block5 marks