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UPSC Civil Services (Mains)

Chemistry optional

  • 2 papers
  • 250 marks each
  • 3 h per paper
  • 5 of 8 questions, Q1 and Q5 compulsory

Paper I covers physical and inorganic chemistry.

UPSC Civil Services (Mains), Chemistry optional · 2023 · Paper I

Q6(a). Completing five reactions of p-block compounds

Question

Complete the following reactions and draw the structure of the major product(s) formed: (i) 2XeF₆ + SiO₂ (50 °C) → ; (ii) NH₄NO₃ (520 K) → ; (iii) N₂O + NaNH₂ (470 K) → ; (iv) 2B₂H₆ + 6NH₃ (180 °C) → ; (v) 6SCl₂ + 16NH₃ → .

Answer in brief

(i) XeOF₄ (+ SiF₄); (ii) N₂O + 2H₂O; (iii) NaN₃ (+ NaOH + NH₃); (iv) B₃N₃H₆ + H₂; (v) S₄N₄ + S + NH₄Cl.

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Read the whole 2023 solution2023 question paper

Topic notes: main group chemistry: boranes, borazine, phosphazenes, silicates, silicones, interhalogens, xenon and sulfur–nitrogen compounds, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coversxenon oxyfluoridenitrous oxidesodium azideborazinetetrasulfur tetranitridep-block reactions

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