UPSC Combined Geo-Scientist
Chemist
- 3 descriptive papers
- 200 marks each
- 3 h per paper
Mains Paper III covers analytical and organic chemistry.
All years
Pages 1 and 2 of 20 
Pages 3 and 4 of 20 
Pages 5 and 6 of 20
Pages 7 and 8 of 20 Pages 9 and 10 of 20 Pages 11 and 12 of 20 Pages 13 and 14 of 20 Pages 15 and 16 of 20 Pages 17 and 18 of 20 Pages 19 and 20 of 20 
Mains Paper III, analytical and organic chemistry
Solution, 2020
UPSC Combined Geo-Scientist, Stage II (Mains). 20 pages. Questions 1, 2, 4, 6, 8 and 10 are answered.
Every question of 2020, one page each51 parts in 10 questions, with the question as text and the key points of its answer
Question 1 40 marks
- 1(a)Significant figures5 marks
- 1(b)Particle diameter in chromatography5 marks
- 1(c)NDIR determination of carbon monoxide5 marks
- 1(d)Thermobalance5 marks
- 1(e)Matrix effects in XRF5 marks
- 1(f)Sample introduction into ICP5 marks
- 1(g)Formation of excited calcium atoms5 marks
- 1(h)Spectrophotometric chromium in a mineral5 marks
Question 2 30 marks
Question 3 30 marks
Question 4 30 marks
Question 5 30 marks
Question 6 40 marks
- 6(a)Dichlorocarbene ring expansion4 marks
- 6(b)Anionic polymerisation of substituted styrenes4 marks
- 6(c)Cyanohydrin formation and hydrolysis4 marks
- 6(d)Doebner condensation4 marks
- 6(e)Hydration with skeletal rearrangement4 marks
- 6(f)Diene reactivity in Diels–Alder reactions4 marks
- 6(g)Norrish II reactivity4 marks
- 6(h)UV maximum of a dienone4 marks
- 6(i)Carbonyl stretching frequencies4 marks
- 6(j)Distinguishing three carbonyl compounds by proton NMR4 marks
Question 7 30 marks
Question 8 30 marks
Question 9 30 marks
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Model answer pages open with the VKC plan.
Model answer pages open with the VKC plan.
Model answer pages open with the VKC plan.
Model answer pages open with the VKC plan.
Model answer pages open with the VKC plan.
Model answer pages open with the VKC plan.
Model answer pages open with the VKC plan.
Printed copy and Kindle
UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025
The book has all five years of Paper III in one volume, with all ten questions of every paper answered, the question printed above each answer, a time plan for each paper, the topic-wise weightage of marks and a topic-wise index.