UPSC Combined Geo-Scientist
Chemist
- 3 descriptive papers
- 200 marks each
- 3 h per paper
Mains Paper III covers analytical and organic chemistry.
All topics
Mains Paper III, analytical and organic chemistry
Outside the listed units: every question, 2016 to 2025
48 parts worth 271 marks have been set on this unit in UPSC Geo-Scientist Chemistry Mains Paper III from 2016 to 2025. Each one opens on its own page with the question, the answer in brief and the key points.
Syllabus
Parts that test something not named in the syllabus.
2020
- Q4(a) Specific surface area of divided cubes5 marks Answered
- Q6(e) Hydration with skeletal rearrangement4 marks Answered
- Q7(d) Reaction sequence via an amide ester with DBU10 marks Question only
2019
- Q1(a) Activity-coefficient trends5 marks Answered
- Q3(a) Potentiometric fluoride measurement10 marks Answered
- Q3(b) Isoelectric and isoionic points5 marks Answered
- Q6(b) Stability of primary carbocations4 marks Answered
- Q6(c) Dehydration of pentan-2-ol4 marks Answered
- Q6(f) Benzyne substitution of p-iodotoluene4 marks Answered
- Q6(i) Heterocycle aromaticity4 marks Answered
- Q7(a) Grignard homologation10 marks Answered
- Q7(b) Pentane-isomer melting points5 marks Answered
- Q7(c) Gabriel route to proline10 marks Answered
- Q8(a) Product and stereochemistry of an alcohol with TsCl/pyridine10 marks Question only
- Q8(b) Pivaloyl chloride with benzene and anisole under AlCl₃10 marks Question only
- Q8(c) Predict products A, B, C and D10 marks Question only
- Q9(c) E2 of menthyl and neomenthyl chlorides5 marks Question only
- Q10(c) Activated Hofmann elimination5 marks Answered
2018
- Q1(g) Alkaline glass-electrode error5 marks Answered
- Q5(a) Indicator electrode in potentiometry10 marks Answered
- Q6(c) Houben–Hoesch acylation4 marks Answered
- Q6(d) Pyrrole: formylation and expansion4 marks Answered
- Q6(h) Pinacol rearrangement pathways4 marks Answered
- Q7(b) Substituted aniline basicity5 marks Answered
- Q7(e) Bucherer amination5 marks Answered
- Q8(a) Increasing stability of carbocations5 marks Question only
- Q8(b) Identify the antiaromatic compound5 marks Question only
- Q9(b) Product and stereochemistry of an acid-catalysed silyl reaction5 marks Question only
- Q9(d) Synthetic sequence for a given transformation5 marks Question only
2017
- Q1(d) Fluoride-selective electrode5 marks Answered
- Q6(a) Nitrophenol acidity5 marks Answered
- Q6(d) Carbocation stability5 marks Answered
- Q6(e) Steric inhibition of resonance5 marks Answered
- Q6(f) Cyclopropenone dipole5 marks Answered
- Q6(g) SN1 and aromatic cations5 marks Answered
- Q6(h) Exhaustive methylation of piperidine5 marks Answered
- Q8(c) Two ring conversions10 marks Question only
2016
- Q1(b) Glass-electrode errors4 marks Answered
- Q1(d) Density of silver4 marks Answered
- Q1(j) Solubility product from potentials4 marks Answered
- Q5(a) Interstitial carbon in iron5 marks Answered
- Q7(a) Acidity and hybridisation4 marks Answered
- Q7(d) Dipole moment of cyclopropenone4 marks Answered
- Q7(g) Keto–enol claim: correction4 marks Answered
- Q8(a) Aromatic, antiaromatic or non-aromatic5 marks Question only
- Q8(b) Order of stability of four carbanions5 marks Question only
- Q8(c) Hinsberg method of separating amines5 marks Question only
- Q11(a) Enhanced acidity of Meldrum acid5 marks Answered
Printed copy and Kindle
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