UPSC Combined Geo-Scientist, Mains · 2021 · Mains Paper I

Q3(c). Sharp lanthanoid spectra

15 marks
Topic: Chemistry of d- and f-block elements
Question only

Question

Why are the electronic spectra of lanthanides sharper as compared to transition metal complexes? Explain by giving suitable reason(s).

Model answer

The free solution for 2021 answers questions 1, 2, 5, 6, 9 and 11, the ones picked in its time plan. Question 3 is answered in full in the Geo-Scientist Chemistry Paper I, 2021 to 2025 book, with every part of every paper.

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UPSC Combined Geo-Scientist (Main) Chemistry Paper I: Model Answers 2021 to 2025

All eleven questions of each paper, with the question printed above its answer
Titration, gravimetric and nuclear numericals worked with units; structures drawn
Topic-wise weightage and a topic-wise index

Printed copy Kindle edition Read sample pages

Topic notes: lanthanides and actinides (lanthanide contraction, magnetic moments, separation), with every Civil Services, IFoS and Geo-Scientist PYQ →

Coverslanthanide spectraf-f transitionsd-d transitionssharp absorption bandsshielding of 4f electrons

All parts of Question 3

3(a) Cobalt complexes: spin states and a charge error5 marks
3(b) d-block diversity and lanthanoid similarity10 marks
3(c) Sharp lanthanoid spectra15 marks