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
Photochemistry: every question, 2021 to 2025
18 parts worth 105 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
Photochemical reactions of simple organic compounds, excited and ground states, singlet and triplet states, Norrish Type I and Type II reactions.
Notes: Organic photochemistry: Norrish reactions (full notes) · short notes
2025
- Q5(c) Photoreduction of benzophenone5 marks Answered
- Q6(a)(i) Photodecarbonylation of thujone5 marks Question only
- Q6(a)(ii) Photochemistry of an amino ketone5 marks Question only
- Q6(a)(iii) Di-pi-methane rearrangement5 marks Question only
2024
- Q5(e) Norrish-II cleavage of a branched aldehyde5 marks Answered
- Q6(c)(i) Photorearrangement of 4-caranone10 marks Question only
- Q6(c)(ii) Substituent effects on Norrish-II reaction5 marks Question only
2023
- Q5(c) Photocyclization of isomesityl oxide5 marks Answered
- Q6(b) Photochemical alpha cleavage10 marks Answered
- Q7(a) Photochemistry of a rigid aryl ketone5 marks Answered
2022
- Q6(d) Norrish-II hydrogen abstraction5 marks Question only
- Q6(e)(i) Photolysis of methyl cyclopropyl ketone5 marks Question only
- Q6(e)(ii) Three-carbon photochemical ring expansion10 marks Question only
2021
- Q1(g) Photochemical cleavage and alkene isomerization5 marks Answered
- Q5(h) Photoproducts of ketone excitation5 marks Answered
- Q7(e) State-dependent diene chemistry and photo-Fries rearrangement5 marks Question only
- Q8(c)(ii) Cyclopentenone photocycloadditions5 marks Question only
- Q8(d) Photochemical cycloaddition and cleavage5 marks Question only