M.Sc. DEGREE EXAMINATION, NOVEMBER 2017
Third Semester
Chemistry
Elective — MOLECULAR PHOTOCHEMISTRY
(CBCS 2014 onwards)
Time 3 Hours Maximum 75 Marks
Part A (10 x 2 20)
Answer all questions.
1. What is meant by intersystem and internal conversion?
2. Explain the terms singlet and triplet state.
3. Predict the products,


4. What is meant by chemiluminescence? Give an example.
5. Explain photoredox reaction.
6. What do you meant by photo chemical conversion?
Sub. Code
4MCH3E2
AFF-4890
2
Wk 14
7. What is photostationary state? Illustrate with an
example.
8. Give any two examples for photochemical isomerisation.
9. Give the advantages of ferrioxalate actinometer.
10. Define actinometry.
Part B x 5 25)
Answer all questions.
11. With the help of a neat Jablonski's diagram explain
the photophysical processes of an excited molecules.
Or
What is triplet state? Explain its involvement in
phosphorescent emission.
12. What is photoreduction? Outline its mechanism.
Or
Briefly explain the formation of oxetane.
13. Discuss the photochemistry of metallocenes.
Or
Explain photo rearrangement reactions with
suitable examples.
14. Explain the Norrish type I photochemical reactions
in carbonyl compounds.
Or
Write notes on Hoffmann-Loefller-Freytag reaction.
AFF-4890
3
Wk 14
15. Describe the working and properties of Reinecke's
salt actinometers.
Or
Write short notes on uranyl oxalate and
photochronic actinometers.
Part C x 10 30)
Answer any three questions.
16. Outline the photophysical kinetics unimolecular
processes.
Differentiate fluorescence and phosphorescence.
17. Explain Woodward-Hoffmann rule.
Discuss the following by taking suitable examples
Photo oxidation
Photo dimerisation. 3.5


Discuss in detail on the photochemistry of transition
metal complexes.
AFF-4890
4
Wk 14
20. Discuss the applications of lasers.
Explain the quality marks of a chemical
actinometer.
————————