UPSC Civil Services (Mains)
Chemistry optional
- 2 papers
- 250 marks each
- 3 h per paper
- 5 of 8 questions, Q1 and Q5 compulsory
Paper II covers organic chemistry and spectroscopy.
All years

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Paper II, organic chemistry and spectroscopy
Solution, 2018
UPSC Civil Services (Mains), Chemistry optional. 24 pages. Questions 1, 2, 4, 5 and 8 are answered on these pages; every question has its full text answer on its own page.
Every question of 2018, one page each35 parts in 8 questions, with the question as text and its full model answer
Question 1 50 marks
- 1(a)π-MO energy levels: benzene, cyclobutadiene, cyclopentadienyl anion10 marks
- 1(b)NBS: preparation and allylic bromination of propene10 marks
- 1(c)Squaric acid; acylation of trans-2-butene10 marks
- 1(d)Thermal [1,3]- and [1,5]-hydrogen shifts10 marks
- 1(e)Photochemical [2+2] cycloaddition of methyl vinyl ketone and ethene10 marks
Question 2 50 marks
Question 3 50 marks
Question 4 50 marks
Question 5 50 marks
- 5(a)Favorskii rearrangement: one product from two chloroketones10 marks
- 5(b)Allylic SN1: kinetic and thermodynamic acetates10 marks
- 5(c)HDPE and LDPE: production, properties, uses10 marks
- 5(d)Chemical shift is independent of the spectrometer frequency10 marks
- 5(e)DNA and RNA: nucleotides, location, functions10 marks
Question 6 50 marks
Question 7 50 marks
Question 8 50 marks























