Indian Forest Service (Mains)
Chemistry optional
- 2 papers
- 200 marks each
- 3 h per paper
Paper II covers organic chemistry and spectroscopy.
All years
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Paper II, organic chemistry and spectroscopy
Question paper, 2023
Indian Forest Service (Mains), Chemistry optional. 10 pages, as issued by UPSC.
Every question of 2023, one page each53 parts in 8 questions, with the question as text and the key points of its answer
Question 1 40 marks
- 1(a)Aromaticity of heterocycles5 marks
- 1(b)Evidence for a tetrahedral intermediate5 marks
- 1(c)Benzyne capture by tetracyclone5 marks
- 1(d)Para-alkyl effects on benzyl solvolysis5 marks
- 1(e)Dehydrobromination through an ion pair5 marks
- 1(f)Why nucleophilic shifts are common5 marks
- 1(g)A double oxy-Cope rearrangement5 marks
- 1(h)Substituent effects in Cannizzaro reaction5 marks
Question 2 40 marks
Question 3 40 marks
- 3(a)Hydrogen bromide addition to a conjugated diene5 marks
- 3(b)(i)Nitration of p-bromoanisole3 marks
- 3(b)(ii)Nitration of p-chloroanisole2 marks
- 3(c)Solvolysis and antiaromatic destabilization5 marks
- 3(d)Racemization during alpha bromination5 marks
- 3(e)Self-condensation of diethyl succinate10 marks
- 3(f)Six-pi electrocyclic switching10 marks
Question 4 40 marks
- 4(a)Two electrophilic additions with unusual outcomes5 marks
- 4(b)Rates of alkoxide-induced elimination5 marks
- 4(c)Regioselective Diels–Alder addition5 marks
- 4(d)Knoevenagel condensation5 marks
- 4(e)Pinacol and Tiffeneau–Demjanov rearrangements5 marks
- 4(f)Buchner ring expansion5 marks
- 4(g)Two substrates, one Favorskii intermediate10 marks
Question 5 40 marks
- 5(a)Substituent effects on anionic propagation5 marks
- 5(b)Osmium dihydroxylation of an allylic alcohol5 marks
- 5(c)Photocyclization of isomesityl oxide5 marks
- 5(d)Woodward–Fieser calculation and a name error5 marks
- 5(e)Distinguishing ortho and para xylene5 marks
- 5(f)Chemical and magnetic equivalence in styrene5 marks
- 5(g)Parent ion from a metastable peak5 marks
- 5(h)Complementary DNA base pairs5 marks
Question 6 40 marks
Question 7 40 marks
- 7(a)Photochemistry of a rigid aryl ketone5 marks
- 7(b)Sequential anionic polymerization5 marks
- 7(c)Neoprene and chloroprene5 marks
- 7(d)Why polymers have average molar masses5 marks
- 7(e)Two unsaturated ester isomers5 marks
- 7(f)Sanger determination of the N terminus5 marks
- 7(g)Chemical-shift separation in Hz5 marks
- 7(h)Hydration of phenylacetylene5 marks