UPSC Civil Services (Mains)
Chemistry optional
- 2 papers
- 250 marks each
- 3 h per paper
- 5 of 8 questions, Q1 and Q5 compulsory
Paper II covers organic chemistry and spectroscopy.
All topics
Paper II, organic chemistry and spectroscopy
Elimination reactions: every question, 2021 to 2025
9 parts worth 85 marks have been set on this unit in UPSC CSE Chemistry Paper II from 2021 to 2025. Each one opens on its own page with the question, the answer in brief and the key points.
Syllabus
E1, E2 and E1cb mechanisms; orientation in E2 reactions: Saytzeff and Hofmann; pyrolytic syn elimination: acetate pyrolysis, Chugaev and Cope eliminations.
Notes: Elimination reactions: E1, E2, E1cB, Saytzeff and Hofmann orientation, syn eliminations (full notes) · short notes
2025
- Q1(b) Missing reagent and intermediates10 marks Answered
- Q1(c) Neomenthyl chloride with sodium ethoxide10 marks Answered
2024
- Q2(b)(ii) Structure of X; name; proof of syn-elimination5 marks Question only
2023
- Q3(c) Regioselectivity of Hofmann elimination by Newman projections10 marks Answered
2022
- Q2(b)(iii) Alkenes from 2-chloro-2,3-dimethylpentane with sodium ethoxide5 marks Question only
- Q3(c)(i) Cl₂CH–CF₃ with ethoxide: product and energy profile10 marks Question only
2021
- Q1(c) 2-Cyclohexylpropan-2-ol with BF₃·OEt₂: products A and B10 marks Answered
- Q2(a) Elimination from trans- and cis-1-chloro-2-methylcyclohexane20 marks Answered
- Q3(c)(i) meso-2,3-Dibromobutane with iodide and with ethoxide5 marks Answered
Printed copy and Kindle
UPSC Civil Services (Main) Chemistry Paper II: Model Answers 2021 to 2025
- All eight questions of each paper, with the question printed above its answer
- Mechanisms drawn out and labelled on the scheme
- Topic-wise weightage and a topic-wise index