UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper III
Q10(d)(i). Mass spectral fragmentation of an ester and a cyclohexene
Question
Explain the mass spectral fragmentation of the following compounds A (an ester) and B (a cyclohexene). [structures given in the paper]
Model answer
The free solution for 2024 answers questions 1, 4, 5, 6, 7 and 9, the ones picked in its time plan. Question 10 is answered in full in the Geo-Scientist Chemistry Paper III, 2021 to 2025 book, with every part of every paper.
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UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025
- All ten questions of each paper, with the question printed above its answer
- Instruments drawn as labelled diagrams, numericals worked with units
- Topic-wise weightage and a topic-wise index
Coversmass spectrometryMcLafferty rearrangementretro-Diels–Alderα-cleavagefragmentation
All parts of Question 10
- 10(a)(i) Anisole with dibromocarbene: ring expansion to a tropone5 marks
- 10(a)(ii) Benzophenone with aluminium isopropoxide at 250 °C5 marks
- 10(b) Structure from ¹H and ¹³C NMR: C₁₅H₁₄O5 marks
- 10(c) Band width and colour; ν(C=O) of acids and ketones5 marks
- 10(d)(i) Mass spectral fragmentation of an ester and a cyclohexene5 marks
- 10(d)(ii) Structure from IR, ¹H and ¹³C NMR: C₁₀H₉NO₂5 marks