UPSC Combined Geo-Scientist, Mains · 2023 · Mains Paper II
Q9(e). Phosphorescence delayed, fluorescence prompt
Question
Justify or criticize the following statement: Phosphorescence is a delayed transition while fluorescence is spontaneous.
Model answer
The free solution for 2023 answers questions 1, 2, 3, 4, 6, 8, 10, 11, 13 and 14, the ones picked in its time plan. Question 9 is answered in full in the Geo-Scientist Chemistry Paper II, 2021 to 2025 book, with every part of every paper.
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UPSC Combined Geo-Scientist (Main) Chemistry Paper II: Model Answers 2021 to 2025
- All fifteen questions of each paper, with the question printed above its answer
- Numericals worked from formula to result with units; graphs with labelled axes
- Topic-wise weightage and a topic-wise index
Coversphosphorescencefluorescenceintersystem crossingtriplet stateJablonski diagram
All parts of Question 9
- 9(a) Half-life method for the order of reaction2 marks
- 9(b) Primary salt effect for persulfate and iodide2 marks
- 9(c) Entropy change on adsorption2 marks
- 9(d) Resonance fluorescence of atoms2 marks
- 9(e) Phosphorescence delayed, fluorescence prompt2 marks