1. NMR signal is obtained in 1,4-dioxane
(a) 3 peaks
(b) 2 peaks
(c) 1 peak
(d) 4 peaks
2. Reference compound used in NMR spectroscopy is
(a) Silane
(b) Trimethylsilane
(c) Dimethylsilane
(d) Tetramethylsilane
3. What is the delta value for TMS in NMR?
(a) 0
(b) 10
(c) 5
(d) 7
4. Radiofrequency radiation is associated with
(a) NMR
(b) IR
(c) Mass spectroscopy
(d) UV
5. Number of NMR signal generated by acetone is
(a) 2
(b) 6
(c) 3
(d) 1
6. The unit of magnetic field strength in NMR is
(a) Cycles/second
(b) Gauss
(c) Pulse/second
(d) Debye
7. Solvent commonly used in NMR is
(a) Chloroform
(b) Methanol
(c) Carbon tetrachloride
(d) Acetone
8. Rotation of electrons about the protons generates a secondary magnetic field which opposes the applied magnetic field. The proton is said to be
(a) Shielded
(b) H-bonded
(c) Deshielded
(d) Shifted
9. What is δ value of aldehyde proton in PMR spectrum?
(a) 1–2
(b) 4–5
(c) 7–8
(d) 9–10
10. Which is the unit of magnetic field?
(a) Gauss
(b) esla
(c) Weber
(d) All of the above
11. Position of signal in NMR spectrum indicates
(a) Number of different kind of the proton present in different environment
(b) Electronic environment of each kind of proton
(c) Relative number of protons of each kind
(d) Number of neighbouring proton present
12. Which compound is used as an internal reference standard for aqueous solution in NMR?
(a) DMSO-d6
(b) CDCl3
(c) 2,2-dimethy-l,2-silapentane-5-sulphonate
(d) Hexachloro acetone
13. Intensities in NMR spectrum indicate
(a) Number of different kinds of the protons present in different environment
(b) Electronic environment of each kind of protons
(c) Relative number of protons of each kind
(d) Number of neighbouring proton present
14. Wave length used in the NMR (nuclear magnetic resonance) is
(a) 1010 nm to 1012 nm
(b) 108 nm to 1010 nm
(c) 1010 µm to 1011 µm
(d) 108 µm to 1010 µm
15. Magic angle NMR is carried out at which angle?
(a) 52.7
(b) 54.7
(c) 56.7
(d) 58.7
16. The number of signals in NMR spectrum indicates _____
(a) Number of different kinds of protons present in different environment
(b) Electronic environment of each kind of proton
(c) Relative number of protons of each kind
(d) Number of neighbouring protons present
17. Which of following has the highest chemical shift (PPM)value?
(a) CH3 I
(b) CH3 Br
(c) CH3 F
(d) CH3 Cl
18. How many PMR peaks are given by 1, 2- dichloro propane?
(a) 2
(b) 3
(c) 4
(d) 5
19. Splitting of signal in NMR spectrum indicates
(a) Number of different kinds of protons present in different environment
(b) Electronic environment of each kind of proton
(c) Relative number of protons of each.
(d) Number of neighbouring protons present
20. Allyl alcohol has how many NMR peaks?
(a) 2
(b) 3
(c) 4
(d) 5
21. Unit of coupling constant is
(a) Cycle per second
(b) Hertz
(c) Both
(d) None of the above
22. PMR of 2-methyl 1-pentene gives how many peaks?
(a) 3
(b) 4
(c) 5
(d) 6
23. Presence of Si in TMS causes
(a) Deshielding and upfield
(b) Deshielding and downfieJd
(c) Shielding and upfield
(d) Shielding and downfield
24. What is the multiplicity expected in the hydrogen NMR spectrum for the hydrogen atoms marked by a
“star” in the following compound?
(a) Singlet
(b) Triplet
(c) Quartet
(d) Heptet
25. Which of following is universal solvent in NMR?
(a) CCI4
(b) DMSO-d6
(c) CDCI3
(d) Hexachloroacetone
26. Unit of chemical shift δ is
(a) Hz
(b) ppm
(c) Cps
(d) Unit less
27. The C13 NMR spectrum of an unknown compound shows 4 absorptions and the H1 NMR spectrum shows 4 absorptions. Which of the following compounds is
the unknown compound?
28. m-dibromo benzene has how many PMR peaks?
(a) 1
(b) 2
(c) 3
(d) 4
29. Presence of electronegative atom on NMR spectra cause
(a) Deshielding and upfield
(b) Deshielding and downfield
(c) Shielding and upfield
(d) hielding and downfield
30. Coupling causes the peaks in 1
H NMR spectra to be split __________
(a) Into two peaks
(b) Into multiple peaks equal to the number of hydrogen on surrounding atoms
(c) Into multiple peaks equal to the number of surrounding carbon atoms
(d) Into multiple peaks equal to the number of hydrogen on surrounding atoms, plus one
31. Environmental effects that occur in NMR is
(a) Chemical shift
(b) hemical exchange
(c) Spin spin splitting
(d) Both (a) and (b)
32. The pressure inside a mass spectrometer is
(a) Lower than atmospheric pressure
(b) Almost nil
(c) Higher than atmospheric pressure
(d) Equal to atmospheric pressure
33. Telsa is a unit to express
(a) Frequency
(b) Pressure
(c) Voltage
(d) Magnetic field strength
34. One of the following compounds gives 3 signals in NMR spectroscopy.
(a) CH3–COOH
(b) CH3 –CH2–NH2
(c) CH3–O–CH3
(d) CH3–CH2–Cl
35. Benzene gives ___________ NMR signal.
(a) 1
(b) 2
(c) 3
(d) 6
36. The number of peaks shown by diethyl ether in an NMR spectrum are is
(a) Four
(b) Two
(c) One
(d) Five
37. Nuclear magnetic moment is not shown by
(a) 13 C
(b) 16 O
(c) 1 H
(d) 15 N
38. In NMR spectroscopy radiation source used is
(a) Radiofrequency source transmitter
(b) Tungsten lamp
(c) Xenon arc lamp
(d) Mercury vapour lamp
39. The method of expressing magnetic field strength is
(a) Cycles/second
(b) Pulses/second
(c) Debye units
(d) Gauss
40. A solvent used in NMR studies is
(a) Chloroform
(b) Acetone
(c) Carbon tetrachloride
(d) Ethanol
41. Rotation of electrons about the proton generates a secondary magnetic field which may oppose the applied magnetic field. The proton is then said to be
(a) Shielded
(b) Shifted
(c) Hydrogen bonded
(d) Deshielded
42. Coupling constant (J) value
(a) Depends upon magnetic field
(b) Is independent of field strength
(c) Depends upon reference standard used
(d) Depends on solvents used
43. Anisotropic effect means
(a) Shielding of protons through space by counter magnetic field
(b) Shielding or deshielding of protons through space by counter magnetic field
(c) Shielding or deshielding of protons through space by applied magnetic field
(d) Shielding of protons through space by applied magnetic field
44. Spin quantum number I of 13C is
(a) 0
(b) 1
(c) 1/2
(d) 3/2
45. 1 Telsa is equal to ______ gauss.
(a) 104
(b) 105
(c) 106
(d) 103
46. Cyclo butane have NMR signal is
(a) 1
(b) 2
(c) 4
(d) 3
47. Coupling constant (J) value is expressed in unit is
(a) Hertz
(b) Cycle per cm
(c) Cycle into second
(d) cm
48. Isotopic composition of 13 C in carbon is
(a) 1.1%
(b) 1.6%
(c) 10%
(d) 0.99%
49. In NMR greater the deshielding of proton,
(a) Larger the value of δ or smaller value of τ
(b) Smaller the value of δ or larger value of τ
(c) Larger the value of δ and larger value of τ
(d) Smaller the value of δ and smaller value of τ
50. 2-bromo propene gives NMR signal is
(a) 2
(b) 3
(c) 4
(d) 6
51. The most intense peak in the mass spectrum is called
(a) Mass peak
(b) Metastable peak
(c) Base peak
(d) M + 1 peak
52. What is nuclear-Zeeman effect in NMR?
(a) Transition from lower energy spin state to higher energy spin state
(b) Splitting of spin states in applied external magnetic field
(c) Splitting of spin states in absence of field
(d) Precessional motion of nuclei in applied magnetic field
53. Which is not a correct statement about chemical shift?
(a) Depends on applied external magnetic field
(b) Does not depend on applied external magnetic field
(c) Dimensionless
(d) Expressed in ppm
54. Correct formula for gyro-magnetic ratio (γ) is
(a) γ = magnetic moment/spin quantum number
(b) γ = magnetic moment/spin angular moment
(c) γ = spin angular moment/magnetic moment
(d) γ = spin quantum number/magnetic moment
55. How many PMR signals will come in NMR spectra of iso-butylene.
(a) 5
(b) 2
(c) 3
(d) 4
56. What is range of chemical shift (δ) in PMR spectra?
(a) 0 to 100
(b) 0 to 200
(c) 0 to 20
(d) 0 to 10
57. How many PMR signals will come in NMR spectra of
vinylchloride?
(a) 2
(b) 3
(c) 4
(d) 5
58. Proton NMR is useful for investigating the structure of organic compounds because ____________
(a) Organic compounds contain carbon atoms
(b) Organic compounds are mostly covalent
(c) Hydrogen atoms are found in nearly all organic compounds
(d) Organic compounds have low boiling points
59. Which of the following statements about tetramethyl-
silane is incorrect?
(a) It produces a single peak at δ =10
(b) It is inert
(c) It is used to provide a reference against which other peaks are measured
(d) It is volatile and can be easily distilled off and used again
60. In a triplet, the relative peak areas are in the ratio_______
(a) 1:1:1
(b) 1:2:1
(c) 1:3:1
(d) 1:4:1
61. All solvents are used to record NMR spectra except:
(a) CDCI3
(b) DMSO-d6
(c) C2H5 OH
(d) Deutariated benzene
1. (c) 2. (b) 3. (a) 4. (a) 5. (d)
6. (b) 7. (c) 8. (a) 9. (d) 10. (d) 11. (b) 12. (c) 13. (c) 14. (a) 15. (b)
16. (a) 17. (c) 18. (c) 19. (d) 20. (d) 21. (c) 22. (d) 23. (c) 24. (c) 25. (b)
26. (b) 27. (d) 28. (c) 29. (b) 30. (d) 31. (d) 32. (b) 33. (d) 34. (b) 35. (a)
36. (b) 37. (b) 38. (a) 39 (d) 40. (c) 41. (a) 42. (b) 43. (c) 44. (c) 45. (b)
46. (a) 47. (a) 48. (a) 49. (a) 50. (b) 51. (c) 52. (b) 53. (a) 54. (b) 55. (b)
56. (d) 57. (b) 58. (c) 59. (a) 60. (b) 61. (c)
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