1. when azide is heated at high temperature then it forms
a. nitrene
b. carbene
c. both
d. none
Correct Answer: a
2. singlet nitrene stability in comparison of triplet is
a. less
b. more
c. both
d. none
Correct Answer: a
3. carbene is specie with carbon having
a. two electrons
b. two bond and one electron
c. two electrons and two bonds
d. two bonds
Correct Answer: c
4. carbene is specie with carbon having
a. negatively charged
b. radical
c. uncharged specie
d. positively charged
Correct Answer: c
5. to which size Bayer’s strain theory is not valid
a. 4 carbon
b. 3 carbon
c. 2 carbon
d. > 6 carbons
Correct Answer: d
6. carbene depend upon
a. magnetic spin
b. both of these
c. none of these
d. electron spin
Correct Answer: d
7. triplet carbenes are
a. none of these
b. paramagnetic
c. diamagnetic
d. both
Correct Answer: b
8. total spin singlet carbene has
a. three
b. none of these
c. zero
d. half
Correct Answer: c
9. total spin of triplet carbene is
a. one
b. zero
c. two
d. none of these
Correct Answer: a
10. singlet carbene are
a. unshared
b. none
c. spin paired
d. spin unpaired
Correct Answer: c
11. which carbene is stable due to back bonding
a. both
b. singlet
c. triplet
d. none
Correct Answer: b
12. carbene is formed in
a. gas phase
b. solution phase
c. solid phase
d. aqeous phase
Correct Answer: d
13. in triplet carbene, vacant p orbitals are
a. not present
b. present
c. filled
d. none
Correct Answer: a
14. stereospecific product is formed in
a. triplet carbene
b. none
c. singlet carbene
d. triplet nitrene
Correct Answer: c
15. what is number of valence electron in carbene
a. sixteen
b. eighteen
c. six
d. eight
Correct Answer: c
16. carbene are very reactive due to
a. filled p orbital
b. partially filled
c. none
d. empty p orbital
Correct Answer: d
17. nitrene are
a. electron efficent
b. radical
c. none of these
d. electron deficient
Correct Answer: d
18. nitrene must be
a. electron efficient
b. neutral
c. electro deficient
d. electron deficent and neutral
Correct Answer: d
19. nitrene is
a. product
b. reactive intermediate
c. catalyst
d. reactant
Correct Answer: b
20. nature of nitrene is
a. uniradical
b. polyradical
c. none of these
d. biradical
Correct Answer: d
21. nitrene are formed usually by
a. hydrazoic acid
b. organic azides
c. none of these
d. both of these
Correct Answer: d
22. hybridization of singlet nitrene is
a. sp
b. none
c. sp2
d. sp3
Correct Answer: c
23. nitrene is – —–stable than carbene
a. more
b. less
c. equal
d. none
Correct Answer: a
24. geometry of singlet nitrene is
a. square planar
b. none
c. triangular
d. tetrahedral
Correct Answer: c
25. triplet nitrene are——stable than singlet nitrene
a. more
b. less
c. equal
d. none
Correct Answer: a
26. in singlet nitrene, decreased stability —–the energy of system
a. increase
b. decrease
c. same
d. no change
Correct Answer: a
27. photochemistry deals with study of
a. light
b. reaction which proceed by adsorption of energy
c. photon
d. electron
Correct Answer: b
28. photochemical reactions take place by adsorption of
a. heat energy
b. electromagnetic radiation
c. UV-Vis light
d. IR radiation
Correct Answer: c
29. emission of light as a result of chemical reaction is called
a. luminescence
b. phosphorescence
c. flourescence
d. chemiluminiscence
Correct Answer: d
30. the light emitted in chemiluminescene is also called as
a. hot light
b. bright light
c. warm light
d. cold light
Correct Answer: d
31. photochemical decomposition of substance is called as
a. thermal reaction
b. photolysis
c. thermolysis
d. thermal dissociation
Correct Answer: b
32. the number of molecules produced per quantum of light adsorbed is known as
a. photon of light
b. quantum yield
c. one quantum
d. einstein
Correct Answer: b
33. for reaction that obeys einstein law
a. Q=0
b. Q=1
c. Q<1
d. Q>1
Correct Answer: b
34. free energy of thermochemical reaction is
a. negative
b. positive
c. zero
d. none
Correct Answer: a
35. first law of photochemistry is known as
a. grotthus-Draper law
b. Stark-Einstein
c. Bear-Lmbert
d. none
Correct Answer: a
36. if excited molecules are deactivated and flouresence stops then it is
a. none
b. Quenching
c. flourescent
d. excited state
Correct Answer: b
37. which is example of photochemical reaction
a. none
b. photosynthesis of carbohydrate
c. photoelectric
d. flouresence
Correct Answer: b
38. energy possessed by one mole of photon is
a. one stark
b. one einstein
c. one joule
d. one newton
Correct Answer: b
39. the number of moles reacting per einstein of light absorbed is called
a. efficiency
b. quantum efficeicy
c. quantum number
d. qquantum value
Correct Answer: b
40. photosyntheis in plants is
a. thermal reaction
b. photochemical
c. electrochemical
d. thermochemical
Correct Answer: b
41. reaction can take place in dark as well in light
a. electrochemicsl
b. none
c. thermal
d. photochemical
Correct Answer: c
42. IC and ISC transition are
a. non radiaitve
b. radiative
c. both of these
d. none
Correct Answer: a
43. has significant effect on rate of chemical reaction
a. pressure
b. concentration
c. temperature
d. volume
Correct Answer: c
44. photochemical changes occur in region of
a. 1000-600nm
b. 400-200nm
c. 1200-400nm
d. 800-200nm
Correct Answer: d
45. which of following is example of phosphorescent material
a. vapur of Na, Hg
b. none
c. zinc sulfide
d. CaF2
Correct Answer: c
46. number of photons that pass through a unit area in unit time
a. intensity of light
b. amplitude of light
c. frequency of light
d. wavelength of light
Correct Answer: a
47. a specie which can absorb and transfer radiant energy for activation of reactant molecule is called
a. none
b. photosensitizer
c. ionizer
d. radioactive
Correct Answer: b
48. flourescence occurs in about —–sec
a. 10-5
b. 10-11
c. 10-3
d. 10-8
Correct Answer: d
49. phosphoresence occurs in about —-sec
a. 10-5
b. 10-11
c. none
d. 10-3
Correct Answer: d
50. the addition of inert gas to absorbing system in photochemical reaction—–the quantum yield
a. increase
b. decrease
c. both
d. none
Correct Answer: a
