M.Sc. First year Chemistry Postgraduate degree course Semester Second Physical Chemistry
Name of Chepter:Photochemistry
Multiple Choice Questions
(a) visible and ultraviolet radiations
(b) Infrared radiations
(c) heat energy
(d) none of these
2. Photochemistry deals with the study of
(a) photons
(b) photos
(c) reactions which proceed with absorptions visible orUV light
(d) reactions which proceed with absorption of IR light
3. The wavelength of ultraviolet and visible regions of electromagnetic spectrum is
(a) less than 2000 Ã…
(b) more than 8000 Ã…
(c) 2000° to 8000 Ã…
(d) none of these
4. Photochemical activation is highly selective. This statement is…
(a) true
(b) false
(c) sometimes true
(d) none of these
5. The number of photons that pass through a unit area in a unit time is called
(a) amplitude of light
(b) frequency of light
(c)intensity of light
(d)wavelength of light
6. The number of molecules reacted or formed per photon of light absorbed is called
(a)yield of the reaction
(b)quantum efficiency
(c)quantum yield
(d)quantum productivity
7. Spin multiplicity can be calculated by using equation
(a)2S-1
(b)2S+1
(c) 2S
(d)2J+1
8. Spin multiplicity value for singlet state is
(a) 1
(b) 2
(c) 0
(d) 3
9. Spin multiplicity value for triplet state is
(a) 1
(b) 2
(c) 0
(d) 3
10. Non radiative process from the following is
(a) Fluorescence
(b) Phosphorescence
(c) Internal conversion
(d) Absorption
11. Radiative process from the following is
(a)Fluorescence
(b)Intersystem crossing
(c) Internal conversion
(d)All
12. Spin inversion of electrons take place in the following process
(a)Internal conversion
(b)Fluorescence
(c)Phosphorescence
(d)None of the above
13. The transition without emission of radiation of a molecule from a stable excited state to an unstable excited state that leads to dissociation
(a)Predissociation
(b)Dissociation
(c)Photo dissociation
(d)None of these
14. What is photo oxidation?
(a)Oxidation of photon
(b)Oxidation without radiation
(c)Oxidation under the influence of radiant energy (such as light)
(d)Photochemical energy
15. Which of the following molecule acts as photosensitizer?
(a)Benzophenone
(b)Acetophenone
(c)Benzene
(d)All of the above
16. Photo oxidation reaction stops in the step
(a)Initiation
(b)Porpogation
(c)Branching
(d)Termination
17. Formation of polycyclic compound in presence of oxygen is an example of….
(a)Photo dissociation
(b)Photo oxidation
(c)Photo cyclization
(d)None of these
18. Which of the following is not photo physical process?
(a)Phosphorescence
(b)Florescence
(c)Internal conversion
(d)All of these
19. Reverse intersystem crossing takes place in
(a)Fluorescence
(b) P type delayed florescence
(c) E type delayed florescence
(d) Phosphorescence
20. E-type delayed fluorescence first observed in….
(a) Enantiomer
(b)Energy levels
(c)Eosin
(d)Ecosin
21.P-type delayed fluorescence first observed in….
(a)Phenol
(b)Phosphorous
(c)P- nitro aniline
(d)Pyrene
22. Slope of straight line drawn between Log(F0)/ Log(F) verses Molarity of sample is….
(a)Stern-Volmer constant
(b)Quenching constant
(c)Stark Einstein constant
(d)None of these
23. In Excimer formation the which species takes part
(a)First Transition series halides
(b)Noble gas halide
(c)IA group halides
(d) None of these
24. Which of the following electronic transition require more energy?
(a)π to π*
(b)σ to σ*
(c) σ to π
(d)n to σ
25. Which of the following electronic transition require less energy?
(a)π to π*
(b) σ to σ*
(c)σ to π
(d)n to σ
