UPSC Civil Services (Mains), Chemistry optional · 2021 · Paper II
Q6(a)(ii). Higher carbonyl stretching frequency in two pairs
Question
Identify the compound in each of the following pairs that can be expected to exhibit the carbonyl stretching signal at higher frequency: I. two six-membered lactones; II. two esters. [structures given in the paper]
Model answer
The free solution for 2021 answers questions 1, 2, 3, 5 and 8, the ones picked in its time plan. Question 6 is answered in full in the Chemistry Paper II, 2021 to 2025 book, with every part of every paper.
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UPSC Civil Services (Main) Chemistry Paper II: Model Answers 2021 to 2025
- All eight questions of each paper, with the question printed above its answer
- Mechanisms drawn out and labelled on the scheme
- Topic-wise weightage and a topic-wise index
CoversIR carbonyl frequencylactoneconjugation effectenol lactoneester C=O stretch
All parts of Question 6
- 6(a)(i) Product of acetone with dilute sodium hydroxide from its spectra15 marks
- 6(a)(ii) Higher carbonyl stretching frequency in two pairs5 marks
- 6(b) Interactions that stabilise a protein, with the residues involved15 marks
- 6(c) I Photolysis of 2-cyclopropylcyclohexanone5 marks
- 6(c) II Photolysis of 1,1,3-triphenylpropan-2-one10 marks