Indian Forest Service (Mains), Chemistry optional · 2022 · Paper I
Q7(b)(ii). Fluxional molecules and variable-temperature NMR
Question
What do you understand by ‘fluxional molecule’? Taking an example of your choice, show how the fluxional behaviour can be characterized with the help of a spectroscopic technique.
Model answer
The free solution for 2022 answers questions 1, 2, 4, 5 and 6, the ones picked in its time plan. Question 7 is answered in full in the IFoS Chemistry Paper I, 2021 to 2025 book, with every part of every paper.
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UPSC Indian Forest Service (Main) Chemistry Paper I: Model Answers 2021 to 2025
- All eight questions of each paper, with the question printed above its answer
- Physical chemistry numericals worked with units; inorganic structures drawn
- Topic-wise weightage and a topic-wise index
Coversfluxional moleculesvariable-temperature NMRBerry pseudorotationPF5dynamic NMR
All parts of Question 7
- 7(a) Adsorption isotherms and BET theory10 marks
- 7(b)(i) Square-planar substitution and trans effect10 marks
- 7(b)(ii) Fluxional molecules and variable-temperature NMR5 marks
- 7(c)(i) Lanthanide oxidation states8 marks
- 7(c)(ii) Sharp weak f–f spectra7 marks