Indian Forest Service (Mains)
Chemistry optional
- 2 papers
- 200 marks each
- 3 h per paper
Paper II covers organic chemistry and spectroscopy.
All topics
Paper II, organic chemistry and spectroscopy
Reactive intermediates: every question, 2021 to 2025
14 parts worth 75 marks have been set on this unit in UPSC IFoS 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
Generation, geometry, stability and reactions of carbonium and carbenium ions, carbanions, free radicals, carbenes, benzynes and nitrenes.
Notes: Reactive intermediates: carbocations, carbanions, radicals, carbenes, nitrenes, benzyne (full notes) · short notes
2025
- Q1(b) Nitrene transfer to an alkene5 marks Answered
2024
- Q1(d) Amination through a benzyne5 marks Answered
- Q2(a)(ii) Kinetic and thermodynamic enolates5 marks Answered
- Q2(b)(i) Photolysis of an ortho-methyl diazo compound5 marks Answered
- Q2(b)(ii) Bridgehead carbocation stability5 marks Answered
2023
- Q1(c) Benzyne capture by tetracyclone5 marks Answered
- Q3(c) Solvolysis and antiaromatic destabilization5 marks Question only
- Q4(f) Buchner ring expansion5 marks Question only
2022
- Q1(d) Dichlorocarbene trapping5 marks Answered
- Q3(a)(ii) Amination through 3,4-pyridyne10 marks Answered
- Q3(e) Stability of three carbanions5 marks Answered
- Q4(d) Benzyne generation and capture5 marks Question only
2021
- Q7(c)(ii) Ring expansion of vinylcyclobutane5 marks Question only
- Q7(d) Stability of triarylmethyl radicals5 marks Question only