Chemistry Exam > Chemistry Notes > Organic Chemistry > Practice Questions on Spectroscopy
Practice Questions on Spectroscopy | Organic Chemistry PDF Download
| Download, print and study this document offline |
Please wait while the PDF view is loading
Page 1
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
Organic Spectroscopy
1. The correct order of the
1
H NMR chemical shift values (d) for the indicated hydrogens (in
bold) in the following compounds is:
(I) (II)
(III) (IV)
(a) I > II > III > IV (b) II > I > III > IV (c) III > II > I > IV (d) II > III > VI > I
2. The correct order of the fundamental vibrational frequency of the following diatomic
molecules is:
(a)
1
H
35
Cl >
1
H
37
Cl >
2
D
35
Cl (b)
2
D
35
Cl >
1
H
37
Cl >
1
H
35
Cl
(c)
1
H
37
Cl >
1
H
35
Cl >
2
D
35
Cl (d)
1
H
37
Cl >
2
D
35
Cl >
1
H
35
Cl
3. Which of the following compound show only two signals in
1
H NMR and a strong IR
bond at ~ 1690 cm
-1
:
(a) (b)
(c) (d)
4. The correct order of
1
H NMR chemical shift (d) values for the labeled methyl groups in
the following compound is:
(a) Me
1
< Me
2
< Me
3
< Me
4
(b) Me
3
< Me
4
< Me
1
< Me
2
(c) Me
3
< Me
1
< Me
4
< Me
2
(d) Me
2
< Me
4
< Me
3
< Me
1
Page 2
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
Organic Spectroscopy
1. The correct order of the
1
H NMR chemical shift values (d) for the indicated hydrogens (in
bold) in the following compounds is:
(I) (II)
(III) (IV)
(a) I > II > III > IV (b) II > I > III > IV (c) III > II > I > IV (d) II > III > VI > I
2. The correct order of the fundamental vibrational frequency of the following diatomic
molecules is:
(a)
1
H
35
Cl >
1
H
37
Cl >
2
D
35
Cl (b)
2
D
35
Cl >
1
H
37
Cl >
1
H
35
Cl
(c)
1
H
37
Cl >
1
H
35
Cl >
2
D
35
Cl (d)
1
H
37
Cl >
2
D
35
Cl >
1
H
35
Cl
3. Which of the following compound show only two signals in
1
H NMR and a strong IR
bond at ~ 1690 cm
-1
:
(a) (b)
(c) (d)
4. The correct order of
1
H NMR chemical shift (d) values for the labeled methyl groups in
the following compound is:
(a) Me
1
< Me
2
< Me
3
< Me
4
(b) Me
3
< Me
4
< Me
1
< Me
2
(c) Me
3
< Me
1
< Me
4
< Me
2
(d) Me
2
< Me
4
< Me
3
< Me
1
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
5. The
1
H NMR spectrum of a compound with molecular formula C 3H7NO shows the
following features:
Chemical shift (ppm) 6.50 2.25 1.10
Shape broad singlet quartet triplet
Which of the following is in agreement with this information:
(a) (CH3)2C = NOH (b) CH3COCH2NH2 (c) CH3CH2CONH2 (d) HCON(CH3)2
6. The two fine–structure components of a nuclear magnetic resonance transition are
observed at chemical shifts of 2.142 and 2.208 ppm in a 300 MHz NMR spectrometer.
Calculate the coupling constant:
(a) 19.8 Hz (b) 0.066 Hz (c) 6.6 Hz (d) date is insufficient
7. A C5H12O2 compound has strong infrared absorption at 3300 to 3400cm
-1
. The
1
H NMR
spectrum has three singlets at d 0.9, d 3.45 and d 3.2 ppm with relative areas 3:2:1.
Addition of D2O to the sample eliminates the lower field signal. The
13
C NMR spectrum
shows three signals all at higher field than d 100 ppm. Which of the following
compounds best fits this data:
(a) 1, 5-pentanediol (b) 1, 3-dimethoxypropane
(c) 2, 2-dimethyl-1, 3-propanediol (d) 2, 4-pentanediol
8. The
1
H NMR spectrum of a compound A shows a doublet and a septet. Which one of the
following statements is true:
(a) The spectrum is consistent with A containing CH 3CH2CH2 group.
(b) The spectrum is consistent with A being (CH3)2 CHCl.
(c) The spectrum is consistent with A containing a CH3CH2 group.
(d) The spectrum is consistent with A being (CH3)2CCl2.
9. A compound of formula C5H12 gives one signal in the
1
H NMR and two signals in the
13
C
NMR spectra. The compound is:
(a) Pentane (b) 2-methylbutane
(c) 2, 2-dimethylpropane (d) Cannot tell without more information
10. The most appropriate spectroscopy for the identification of a nitrile group is:
(a) IR (b)
1
H NMR (c) UV (d) ESR
11. Compound I gives a strong infrared absorption at 1730 cm
-1
.
1
H NMR spectrum indicates
that it has two types of hydrogen atoms; one H atom appearing as signlet at d = 9.7 ppm
and 9H atoms appearing as a singlet at d = 1.2 ppm. The structure of I is:
(a) (b) (c) (d)
Page 3
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
Organic Spectroscopy
1. The correct order of the
1
H NMR chemical shift values (d) for the indicated hydrogens (in
bold) in the following compounds is:
(I) (II)
(III) (IV)
(a) I > II > III > IV (b) II > I > III > IV (c) III > II > I > IV (d) II > III > VI > I
2. The correct order of the fundamental vibrational frequency of the following diatomic
molecules is:
(a)
1
H
35
Cl >
1
H
37
Cl >
2
D
35
Cl (b)
2
D
35
Cl >
1
H
37
Cl >
1
H
35
Cl
(c)
1
H
37
Cl >
1
H
35
Cl >
2
D
35
Cl (d)
1
H
37
Cl >
2
D
35
Cl >
1
H
35
Cl
3. Which of the following compound show only two signals in
1
H NMR and a strong IR
bond at ~ 1690 cm
-1
:
(a) (b)
(c) (d)
4. The correct order of
1
H NMR chemical shift (d) values for the labeled methyl groups in
the following compound is:
(a) Me
1
< Me
2
< Me
3
< Me
4
(b) Me
3
< Me
4
< Me
1
< Me
2
(c) Me
3
< Me
1
< Me
4
< Me
2
(d) Me
2
< Me
4
< Me
3
< Me
1
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
5. The
1
H NMR spectrum of a compound with molecular formula C 3H7NO shows the
following features:
Chemical shift (ppm) 6.50 2.25 1.10
Shape broad singlet quartet triplet
Which of the following is in agreement with this information:
(a) (CH3)2C = NOH (b) CH3COCH2NH2 (c) CH3CH2CONH2 (d) HCON(CH3)2
6. The two fine–structure components of a nuclear magnetic resonance transition are
observed at chemical shifts of 2.142 and 2.208 ppm in a 300 MHz NMR spectrometer.
Calculate the coupling constant:
(a) 19.8 Hz (b) 0.066 Hz (c) 6.6 Hz (d) date is insufficient
7. A C5H12O2 compound has strong infrared absorption at 3300 to 3400cm
-1
. The
1
H NMR
spectrum has three singlets at d 0.9, d 3.45 and d 3.2 ppm with relative areas 3:2:1.
Addition of D2O to the sample eliminates the lower field signal. The
13
C NMR spectrum
shows three signals all at higher field than d 100 ppm. Which of the following
compounds best fits this data:
(a) 1, 5-pentanediol (b) 1, 3-dimethoxypropane
(c) 2, 2-dimethyl-1, 3-propanediol (d) 2, 4-pentanediol
8. The
1
H NMR spectrum of a compound A shows a doublet and a septet. Which one of the
following statements is true:
(a) The spectrum is consistent with A containing CH 3CH2CH2 group.
(b) The spectrum is consistent with A being (CH3)2 CHCl.
(c) The spectrum is consistent with A containing a CH3CH2 group.
(d) The spectrum is consistent with A being (CH3)2CCl2.
9. A compound of formula C5H12 gives one signal in the
1
H NMR and two signals in the
13
C
NMR spectra. The compound is:
(a) Pentane (b) 2-methylbutane
(c) 2, 2-dimethylpropane (d) Cannot tell without more information
10. The most appropriate spectroscopy for the identification of a nitrile group is:
(a) IR (b)
1
H NMR (c) UV (d) ESR
11. Compound I gives a strong infrared absorption at 1730 cm
-1
.
1
H NMR spectrum indicates
that it has two types of hydrogen atoms; one H atom appearing as signlet at d = 9.7 ppm
and 9H atoms appearing as a singlet at d = 1.2 ppm. The structure of I is:
(a) (b) (c) (d)
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
12. The functionality that shows a typical characteristic peak at 2250 cm
-1
in IR is:
(a) (b) CHO (c) NCO (d) N3
13. Consider a
1
H NMR spectrum in which a quartet and a doublet appeared at 9.72 and 2.40
ppm, respectively. Which of the following compounds is the most probable one:
(a) CH3COCH3 (b) CH3CH2CHO (c) CH3CHO (d) CH3CH2CH2OH
14. The order of decreasing chemicals shift in
1
H NMR for the underlined hydrogens is:
(I) H3C – CH2 – CH3 (II) H3 C – O – CH2 – CH3
(III) Cl 2 – CH – O – CH2 – CH3 (IV) Cl – CH2 – O – CH2 – CH3
(a) II > III > I > IV (b) II > III > IV > I (c) III > II > I > IV (d) III > IV > II > I
15. The number of normal modes of vibration in the benzene molecule is:
(a) 6 (b) 30 (c) 12 (d) 36
16. An organic compound (MF: C8H10O) exhibited the following
1
H NMR spectral data: d
2.5 (3 H,s), 3.8 (3H, s), 6.8 (2 H, d, J 8 Hz), 7.2 (2 H, d, J 8 Hz) ppm. The compound
among the choices is:
(a) 4-ethylphenol (b) 2-ethylphenol
(c) 4-methylanisole (d) 4-methylbenzyl alcohol
17. The
1
H NMR spectrum of 1, 4-dimethoxybenzene will have:
(a) Ten singlets (b) Two singlets
(c) Two doublets and one singlet (d) Two doublets and two singlet
18. Appropriate
1
H NMR chemical shifts (d) for the protons A-D for the following compound
are:
(a) A–6.8; B–5.7; C–3.9; D–2.1ppm (b) A–6.8; B–5.7; C–2.1; D–3.9ppm
(c) A–5.7; B–6.8; C–3.9; D–2.1ppm (d) A–5.7; B–6.8; C–2.1; D–3.9ppm
19. Compound A and B exhibit two singlets, each in their
1
H NMR spectra. The expected
chemical shifts are at d:
(A) (B)
(a) 6.9 and 2.1 for A; 7.7 and 3.9 for B (b) 7.7 and 3.9 for A; 6.9 and 2.1 for B
(c) 6.9 and 3.9 for A; 7.7 and 2.1 for B (d) 7.7 and 2.1 for A; 6.9 and 3.9 for B
Page 4
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
Organic Spectroscopy
1. The correct order of the
1
H NMR chemical shift values (d) for the indicated hydrogens (in
bold) in the following compounds is:
(I) (II)
(III) (IV)
(a) I > II > III > IV (b) II > I > III > IV (c) III > II > I > IV (d) II > III > VI > I
2. The correct order of the fundamental vibrational frequency of the following diatomic
molecules is:
(a)
1
H
35
Cl >
1
H
37
Cl >
2
D
35
Cl (b)
2
D
35
Cl >
1
H
37
Cl >
1
H
35
Cl
(c)
1
H
37
Cl >
1
H
35
Cl >
2
D
35
Cl (d)
1
H
37
Cl >
2
D
35
Cl >
1
H
35
Cl
3. Which of the following compound show only two signals in
1
H NMR and a strong IR
bond at ~ 1690 cm
-1
:
(a) (b)
(c) (d)
4. The correct order of
1
H NMR chemical shift (d) values for the labeled methyl groups in
the following compound is:
(a) Me
1
< Me
2
< Me
3
< Me
4
(b) Me
3
< Me
4
< Me
1
< Me
2
(c) Me
3
< Me
1
< Me
4
< Me
2
(d) Me
2
< Me
4
< Me
3
< Me
1
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
5. The
1
H NMR spectrum of a compound with molecular formula C 3H7NO shows the
following features:
Chemical shift (ppm) 6.50 2.25 1.10
Shape broad singlet quartet triplet
Which of the following is in agreement with this information:
(a) (CH3)2C = NOH (b) CH3COCH2NH2 (c) CH3CH2CONH2 (d) HCON(CH3)2
6. The two fine–structure components of a nuclear magnetic resonance transition are
observed at chemical shifts of 2.142 and 2.208 ppm in a 300 MHz NMR spectrometer.
Calculate the coupling constant:
(a) 19.8 Hz (b) 0.066 Hz (c) 6.6 Hz (d) date is insufficient
7. A C5H12O2 compound has strong infrared absorption at 3300 to 3400cm
-1
. The
1
H NMR
spectrum has three singlets at d 0.9, d 3.45 and d 3.2 ppm with relative areas 3:2:1.
Addition of D2O to the sample eliminates the lower field signal. The
13
C NMR spectrum
shows three signals all at higher field than d 100 ppm. Which of the following
compounds best fits this data:
(a) 1, 5-pentanediol (b) 1, 3-dimethoxypropane
(c) 2, 2-dimethyl-1, 3-propanediol (d) 2, 4-pentanediol
8. The
1
H NMR spectrum of a compound A shows a doublet and a septet. Which one of the
following statements is true:
(a) The spectrum is consistent with A containing CH 3CH2CH2 group.
(b) The spectrum is consistent with A being (CH3)2 CHCl.
(c) The spectrum is consistent with A containing a CH3CH2 group.
(d) The spectrum is consistent with A being (CH3)2CCl2.
9. A compound of formula C5H12 gives one signal in the
1
H NMR and two signals in the
13
C
NMR spectra. The compound is:
(a) Pentane (b) 2-methylbutane
(c) 2, 2-dimethylpropane (d) Cannot tell without more information
10. The most appropriate spectroscopy for the identification of a nitrile group is:
(a) IR (b)
1
H NMR (c) UV (d) ESR
11. Compound I gives a strong infrared absorption at 1730 cm
-1
.
1
H NMR spectrum indicates
that it has two types of hydrogen atoms; one H atom appearing as signlet at d = 9.7 ppm
and 9H atoms appearing as a singlet at d = 1.2 ppm. The structure of I is:
(a) (b) (c) (d)
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
12. The functionality that shows a typical characteristic peak at 2250 cm
-1
in IR is:
(a) (b) CHO (c) NCO (d) N3
13. Consider a
1
H NMR spectrum in which a quartet and a doublet appeared at 9.72 and 2.40
ppm, respectively. Which of the following compounds is the most probable one:
(a) CH3COCH3 (b) CH3CH2CHO (c) CH3CHO (d) CH3CH2CH2OH
14. The order of decreasing chemicals shift in
1
H NMR for the underlined hydrogens is:
(I) H3C – CH2 – CH3 (II) H3 C – O – CH2 – CH3
(III) Cl 2 – CH – O – CH2 – CH3 (IV) Cl – CH2 – O – CH2 – CH3
(a) II > III > I > IV (b) II > III > IV > I (c) III > II > I > IV (d) III > IV > II > I
15. The number of normal modes of vibration in the benzene molecule is:
(a) 6 (b) 30 (c) 12 (d) 36
16. An organic compound (MF: C8H10O) exhibited the following
1
H NMR spectral data: d
2.5 (3 H,s), 3.8 (3H, s), 6.8 (2 H, d, J 8 Hz), 7.2 (2 H, d, J 8 Hz) ppm. The compound
among the choices is:
(a) 4-ethylphenol (b) 2-ethylphenol
(c) 4-methylanisole (d) 4-methylbenzyl alcohol
17. The
1
H NMR spectrum of 1, 4-dimethoxybenzene will have:
(a) Ten singlets (b) Two singlets
(c) Two doublets and one singlet (d) Two doublets and two singlet
18. Appropriate
1
H NMR chemical shifts (d) for the protons A-D for the following compound
are:
(a) A–6.8; B–5.7; C–3.9; D–2.1ppm (b) A–6.8; B–5.7; C–2.1; D–3.9ppm
(c) A–5.7; B–6.8; C–3.9; D–2.1ppm (d) A–5.7; B–6.8; C–2.1; D–3.9ppm
19. Compound A and B exhibit two singlets, each in their
1
H NMR spectra. The expected
chemical shifts are at d:
(A) (B)
(a) 6.9 and 2.1 for A; 7.7 and 3.9 for B (b) 7.7 and 3.9 for A; 6.9 and 2.1 for B
(c) 6.9 and 3.9 for A; 7.7 and 2.1 for B (d) 7.7 and 2.1 for A; 6.9 and 3.9 for B
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
20. In the
1
H NMR spectrum recorded at 293 K, an organic compound (C 3H7NO), exhibited
signals at d 7.8 (1H, s), 2.8 (3H, s) and 2.6 (3H, s). The compound is:
(a) (b) (c) (d)
21. An organic compound exhibited the following
1
H NMR spectra data:
d 7.80 (2 H, d, J = 8 Hz), 6.80 (2 H, d, J = 8 Hz), 4.10 (2 H, q, J = 7.2 Hz),
2.4 (3H, s), 1.25 (3 H, t, J = 7.2 Hz)
The compound, among the choices given below is,
(a) (b)
(c) (d)
22. In NMR spectroscopy the product the nuclear ‘g’ factor (gN), the nuclear magneton (ßN)
and the magnetic field strength (B0) gives the:
(a) Energy of transition from a to ß state (b) Chemical shift
(c) Spin–Spin coupling constant (d) Magnetogyric ratio
23. Among the isomers of C4H6 given below, the compound which exhibits an absorption
band at 3300 cm
-1
in the IR spectrum, is:
(a) 1, 3-butadiene (b) 1-butyne (c) 2-butyne (d) cyclobutane.
24. Match the compounds P–S with their carbonyl stretching frequencies (cm
-1
) I–VI in IR
spectroscopy:
P. Acetone I. 1870
Q. Ethyl acetate II. 1800
R. Acetamide III. 1740
S. Acetyl chloride IV. 1700
V. 1660
VI. 1600
(a) P–IV, Q–III, R–I, S–VI (b) P–III, Q–VI, R–V, S–II
(c) P–IV, Q–III, R–V, S–II (d) P–II, Q–V, R–III, S–VI
25. Out of the following, the one which is not an excitation source for IR spectra is:
(a) Tungsten filament lamp (b) Nernst glower
(c) Deuterium lamp (d) Mercury arc.
Page 5
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
Organic Spectroscopy
1. The correct order of the
1
H NMR chemical shift values (d) for the indicated hydrogens (in
bold) in the following compounds is:
(I) (II)
(III) (IV)
(a) I > II > III > IV (b) II > I > III > IV (c) III > II > I > IV (d) II > III > VI > I
2. The correct order of the fundamental vibrational frequency of the following diatomic
molecules is:
(a)
1
H
35
Cl >
1
H
37
Cl >
2
D
35
Cl (b)
2
D
35
Cl >
1
H
37
Cl >
1
H
35
Cl
(c)
1
H
37
Cl >
1
H
35
Cl >
2
D
35
Cl (d)
1
H
37
Cl >
2
D
35
Cl >
1
H
35
Cl
3. Which of the following compound show only two signals in
1
H NMR and a strong IR
bond at ~ 1690 cm
-1
:
(a) (b)
(c) (d)
4. The correct order of
1
H NMR chemical shift (d) values for the labeled methyl groups in
the following compound is:
(a) Me
1
< Me
2
< Me
3
< Me
4
(b) Me
3
< Me
4
< Me
1
< Me
2
(c) Me
3
< Me
1
< Me
4
< Me
2
(d) Me
2
< Me
4
< Me
3
< Me
1
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
5. The
1
H NMR spectrum of a compound with molecular formula C 3H7NO shows the
following features:
Chemical shift (ppm) 6.50 2.25 1.10
Shape broad singlet quartet triplet
Which of the following is in agreement with this information:
(a) (CH3)2C = NOH (b) CH3COCH2NH2 (c) CH3CH2CONH2 (d) HCON(CH3)2
6. The two fine–structure components of a nuclear magnetic resonance transition are
observed at chemical shifts of 2.142 and 2.208 ppm in a 300 MHz NMR spectrometer.
Calculate the coupling constant:
(a) 19.8 Hz (b) 0.066 Hz (c) 6.6 Hz (d) date is insufficient
7. A C5H12O2 compound has strong infrared absorption at 3300 to 3400cm
-1
. The
1
H NMR
spectrum has three singlets at d 0.9, d 3.45 and d 3.2 ppm with relative areas 3:2:1.
Addition of D2O to the sample eliminates the lower field signal. The
13
C NMR spectrum
shows three signals all at higher field than d 100 ppm. Which of the following
compounds best fits this data:
(a) 1, 5-pentanediol (b) 1, 3-dimethoxypropane
(c) 2, 2-dimethyl-1, 3-propanediol (d) 2, 4-pentanediol
8. The
1
H NMR spectrum of a compound A shows a doublet and a septet. Which one of the
following statements is true:
(a) The spectrum is consistent with A containing CH 3CH2CH2 group.
(b) The spectrum is consistent with A being (CH3)2 CHCl.
(c) The spectrum is consistent with A containing a CH3CH2 group.
(d) The spectrum is consistent with A being (CH3)2CCl2.
9. A compound of formula C5H12 gives one signal in the
1
H NMR and two signals in the
13
C
NMR spectra. The compound is:
(a) Pentane (b) 2-methylbutane
(c) 2, 2-dimethylpropane (d) Cannot tell without more information
10. The most appropriate spectroscopy for the identification of a nitrile group is:
(a) IR (b)
1
H NMR (c) UV (d) ESR
11. Compound I gives a strong infrared absorption at 1730 cm
-1
.
1
H NMR spectrum indicates
that it has two types of hydrogen atoms; one H atom appearing as signlet at d = 9.7 ppm
and 9H atoms appearing as a singlet at d = 1.2 ppm. The structure of I is:
(a) (b) (c) (d)
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
12. The functionality that shows a typical characteristic peak at 2250 cm
-1
in IR is:
(a) (b) CHO (c) NCO (d) N3
13. Consider a
1
H NMR spectrum in which a quartet and a doublet appeared at 9.72 and 2.40
ppm, respectively. Which of the following compounds is the most probable one:
(a) CH3COCH3 (b) CH3CH2CHO (c) CH3CHO (d) CH3CH2CH2OH
14. The order of decreasing chemicals shift in
1
H NMR for the underlined hydrogens is:
(I) H3C – CH2 – CH3 (II) H3 C – O – CH2 – CH3
(III) Cl 2 – CH – O – CH2 – CH3 (IV) Cl – CH2 – O – CH2 – CH3
(a) II > III > I > IV (b) II > III > IV > I (c) III > II > I > IV (d) III > IV > II > I
15. The number of normal modes of vibration in the benzene molecule is:
(a) 6 (b) 30 (c) 12 (d) 36
16. An organic compound (MF: C8H10O) exhibited the following
1
H NMR spectral data: d
2.5 (3 H,s), 3.8 (3H, s), 6.8 (2 H, d, J 8 Hz), 7.2 (2 H, d, J 8 Hz) ppm. The compound
among the choices is:
(a) 4-ethylphenol (b) 2-ethylphenol
(c) 4-methylanisole (d) 4-methylbenzyl alcohol
17. The
1
H NMR spectrum of 1, 4-dimethoxybenzene will have:
(a) Ten singlets (b) Two singlets
(c) Two doublets and one singlet (d) Two doublets and two singlet
18. Appropriate
1
H NMR chemical shifts (d) for the protons A-D for the following compound
are:
(a) A–6.8; B–5.7; C–3.9; D–2.1ppm (b) A–6.8; B–5.7; C–2.1; D–3.9ppm
(c) A–5.7; B–6.8; C–3.9; D–2.1ppm (d) A–5.7; B–6.8; C–2.1; D–3.9ppm
19. Compound A and B exhibit two singlets, each in their
1
H NMR spectra. The expected
chemical shifts are at d:
(A) (B)
(a) 6.9 and 2.1 for A; 7.7 and 3.9 for B (b) 7.7 and 3.9 for A; 6.9 and 2.1 for B
(c) 6.9 and 3.9 for A; 7.7 and 2.1 for B (d) 7.7 and 2.1 for A; 6.9 and 3.9 for B
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
20. In the
1
H NMR spectrum recorded at 293 K, an organic compound (C 3H7NO), exhibited
signals at d 7.8 (1H, s), 2.8 (3H, s) and 2.6 (3H, s). The compound is:
(a) (b) (c) (d)
21. An organic compound exhibited the following
1
H NMR spectra data:
d 7.80 (2 H, d, J = 8 Hz), 6.80 (2 H, d, J = 8 Hz), 4.10 (2 H, q, J = 7.2 Hz),
2.4 (3H, s), 1.25 (3 H, t, J = 7.2 Hz)
The compound, among the choices given below is,
(a) (b)
(c) (d)
22. In NMR spectroscopy the product the nuclear ‘g’ factor (gN), the nuclear magneton (ßN)
and the magnetic field strength (B0) gives the:
(a) Energy of transition from a to ß state (b) Chemical shift
(c) Spin–Spin coupling constant (d) Magnetogyric ratio
23. Among the isomers of C4H6 given below, the compound which exhibits an absorption
band at 3300 cm
-1
in the IR spectrum, is:
(a) 1, 3-butadiene (b) 1-butyne (c) 2-butyne (d) cyclobutane.
24. Match the compounds P–S with their carbonyl stretching frequencies (cm
-1
) I–VI in IR
spectroscopy:
P. Acetone I. 1870
Q. Ethyl acetate II. 1800
R. Acetamide III. 1740
S. Acetyl chloride IV. 1700
V. 1660
VI. 1600
(a) P–IV, Q–III, R–I, S–VI (b) P–III, Q–VI, R–V, S–II
(c) P–IV, Q–III, R–V, S–II (d) P–II, Q–V, R–III, S–VI
25. Out of the following, the one which is not an excitation source for IR spectra is:
(a) Tungsten filament lamp (b) Nernst glower
(c) Deuterium lamp (d) Mercury arc.
2637, Hudson Lane, Behind Khalsa College, Near G.T.B. Nagar Metro Station Gate No. 3 & 4, New Delhi – 110009
Mob. 011-47455430, 08860929430, e-mail: info@asfinstitute.com, www.asfinstitute.com
26. The molecular active in rotational microwave, infrared absorption as well as rotational
Raman spectra is:
(a) CO2 (b) SF6 (c) HCl (d) H2
27. Which of the following absorptions is shown by 1, 3-butadiene in its UV absorption
spectrum recorded in n-hexane (
max
? is the molar absorptivity):
(a) ?max217nm(
max
? = 21,000) (b) ?max214nm(
max
? = 210)
(c) ?max253nm(
max
? = 50,000) (d) ?max250nm(
max
? = 500)
28. Match the compounds in List –I with the stretching frequencies (cm
-1
) of the principal
functional groups given in List –II:
List – I List – II
(1) (i) 2240
(2) (ii) 1795
(3) (iii) 1750
(4) (iv) 1725
(v) 1695
(a) 1-iii, 2-iv, 3-i, 4-v (b) 1-iii, 2-iv, 3-ii, 4-v
(c) 1-vi, 2-v, 3-ii, 4-i (d) 1-vi, 2-iii, 3-v, 4-i
29. Match the observed principal absorptions in the visible spectrum shown in List-I with the
bond shows this absorption in List –II:
List – I List – II
(1) ? ?
*
? (i) C–C
(2) n ?
*
? (ii) C–O
(3) n, p* (iii) C=O
(4) p, p* (iv) C=C
(a) 1-(i), 2-(ii), 3-(iii), 4-(iv) (b) 1-(i), 2-(iii), 3-(ii), 4-(iv)
(c) 1-(ii), 2-(i), 3-(vi), 4-(iii) (d) 1-(vi), 2-(ii), 3-(iii), 4-(i)
Read More
|
44 videos|102 docs|52 tests
|
FAQs on Practice Questions on Spectroscopy - Organic Chemistry
| 1. What is spectroscopy and why is it important in chemistry? |  |
Ans. Spectroscopy is the study of the interaction between matter and electromagnetic radiation. It is important in chemistry as it allows scientists to analyze the composition, structure, and properties of substances by studying the way they interact with light. By using spectroscopic techniques, chemists can identify and characterize chemical compounds, determine their concentration, and study their chemical reactions.
| 2. What are the different types of spectroscopy? | |
Ans. There are several types of spectroscopy, including:
- Absorption Spectroscopy: Measures the absorption of light by a substance to identify its composition and concentration.
- Emission Spectroscopy: Measures the emission of light from a substance to study its energy levels and electronic transitions.
- Fluorescence Spectroscopy: Measures the emission of light after a substance absorbs light of a specific wavelength, used for studying fluorescent compounds.
- Infrared Spectroscopy: Measures the absorption of infrared radiation by a substance to identify functional groups and molecular structures.
- Nuclear Magnetic Resonance (NMR) Spectroscopy: Analyzes the magnetic properties of atomic nuclei to determine the chemical structure and composition of a substance.
| 3. How does spectroscopy work? | |
Ans. Spectroscopy works by passing a beam of light (or electromagnetic radiation) through a sample and measuring the interaction between the light and the sample. The sample absorbs certain wavelengths of light, which correspond to specific energy levels or vibrations within the molecules. The absorbed or emitted light is then detected and analyzed to determine the composition, structure, or properties of the sample.
| 4. What are the applications of spectroscopy? | |
Ans. Spectroscopy has numerous applications in various fields, including:
- Analytical Chemistry: Used for qualitative and quantitative analysis of chemical compounds.
- Environmental Science: Helps in identifying pollutants and monitoring environmental contaminants.
- Pharmaceutical Industry: Used for drug discovery, quality control, and formulation analysis.
- Astrophysics: Used for studying the composition and properties of celestial objects.
- Forensic Science: Helps in analyzing and identifying unknown substances at crime scenes.
- Medical Diagnosis: Used in medical imaging techniques like MRI and PET scans.
| 5. How can spectroscopy be used to determine molecular structures? | |
Ans. Spectroscopy can be used to determine molecular structures by analyzing the absorption or emission spectra of a substance. Each molecule has a unique set of energy levels, and the transitions between these levels result in the absorption or emission of specific wavelengths of light. By studying the pattern of absorption or emission lines in the spectrum, scientists can deduce the types of bonds, functional groups, and overall structure of the molecule. Techniques like infrared spectroscopy and NMR spectroscopy are particularly useful for determining molecular structures.
About this Document
2.3K Views
4.67/5
Rating
Oct 05, 2025
Last updated
Related Exams
Document Description: Practice Questions on Spectroscopy for Chemistry 2025 is part of Organic Chemistry preparation.
The notes and questions for Practice Questions on Spectroscopy have been prepared according to the Chemistry exam syllabus. Information about Practice Questions on Spectroscopy covers topics
like and Practice Questions on Spectroscopy Example, for Chemistry 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises and tests below for Practice Questions on Spectroscopy.
Introduction of Practice Questions on Spectroscopy in English is available as part of our Organic Chemistry
for Chemistry & Practice Questions on Spectroscopy in Hindi for Organic Chemistry course.
Download more important topics related with notes, lectures and mock test series for Chemistry
Exam by signing up for free. Chemistry: Practice Questions on Spectroscopy | Organic Chemistry
Description
Full syllabus notes, lecture & questions for Practice Questions on Spectroscopy | Organic Chemistry - Chemistry | Plus excerises question with solution to help you revise complete syllabus for Organic Chemistry | Best notes, free PDF download
Information about Practice Questions on Spectroscopy
In this doc you can find the meaning of Practice Questions on Spectroscopy defined & explained in the simplest way possible. Besides explaining types of
Practice Questions on Spectroscopy theory, EduRev gives you an ample number of questions to practice Practice Questions on Spectroscopy tests, examples and also practice Chemistry
tests
Related Searches
MCQs
,Sample Paper
,shortcuts and tricks
,video lectures
,Practice Questions on Spectroscopy | Organic Chemistry
,practice quizzes
,Practice Questions on Spectroscopy | Organic Chemistry
,mock tests for examination
,Exam
,Viva Questions
,ppt
,Previous Year Questions with Solutions
,Summary
,Important questions
,Free
,Objective type Questions
,Practice Questions on Spectroscopy | Organic Chemistry
,study material
,Extra Questions
,Semester Notes
,past year papers
;
Additional Information about Practice Questions on Spectroscopy for Chemistry Preparation
Practice Questions on Spectroscopy Free PDF Download
The Practice Questions on Spectroscopy is an invaluable resource that delves deep into the core of the Chemistry exam.
These study notes are curated by experts and cover all the essential topics and concepts, making your preparation more efficient and effective.
With the help of these notes, you can grasp complex subjects quickly, revise important points easily,
and reinforce your understanding of key concepts. The study notes are presented in a concise and easy-to-understand manner,
allowing you to optimize your learning process. Whether you're looking for best-recommended books, sample papers, study material,
or toppers' notes, this PDF has got you covered. Download the Practice Questions on Spectroscopy now and kickstart your journey towards success in the Chemistry exam.
Importance of Practice Questions on Spectroscopy
The importance of Practice Questions on Spectroscopy cannot be overstated, especially for Chemistry aspirants.
This document holds the key to success in the Chemistry exam.
It offers a detailed understanding of the concept, providing invaluable insights into the topic.
By knowing the concepts well in advance, students can plan their preparation effectively.
Utilize this indispensable guide for a well-rounded preparation and achieve your desired results.
Practice Questions on Spectroscopy Notes
Practice Questions on Spectroscopy Notes offer in-depth insights into the specific topic to help you master it with ease.
This comprehensive document covers all aspects related to Practice Questions on Spectroscopy.
It includes detailed information about the exam syllabus, recommended books, and study materials for a well-rounded preparation.
Practice papers and question papers enable you to assess your progress effectively.
Additionally, the paper analysis provides valuable tips for tackling the exam strategically.
Access to Toppers' notes gives you an edge in understanding complex concepts.
Whether you're a beginner or aiming for advanced proficiency, Practice Questions on Spectroscopy Notes on EduRev are your ultimate resource for success.
Practice Questions on Spectroscopy Chemistry
The "Practice Questions on Spectroscopy Chemistry Questions" guide is a valuable resource for all aspiring students preparing for the
Chemistry exam. It focuses on providing a wide range of practice questions to help students gauge
their understanding of the exam topics. These questions cover the entire syllabus, ensuring comprehensive preparation.
The guide includes previous years' question papers for students to familiarize themselves with the exam's format and difficulty level.
Additionally, it offers subject-specific question banks, allowing students to focus on weak areas and improve their performance.
Study Practice Questions on Spectroscopy on the App
Students of Chemistry can study Practice Questions on Spectroscopy alongwith tests & analysis from the EduRev app,
which will help them while preparing for their exam. Apart from the Practice Questions on Spectroscopy,
students can also utilize the EduRev App for other study materials such as previous year question papers, syllabus, important questions, etc.
The EduRev App will make your learning easier as you can access it from anywhere you want.
The content of Practice Questions on Spectroscopy is prepared as per the latest Chemistry syllabus.
|
© EduRev
|
Education Revolution
|
|
Signup on EduRev and stay on top of your study goals
10M+ students crushing their study goals daily