Question 1

Deduce the identity of the following compound from the 13C NMR data given.
C4H8O: δ 11.97 (triplet), 33.54 (triplet), 67.03 (doublet) (ppm)

Accepted Answer

Question 2

Deduce the identity of the following compound from the spectral data given.
C9H10O2: 13C NMR, δ 18.06 (quartet), 45.40 (doublet), 127.32 (doublet), 127.55 (doublet), 128.61 (doublet), 139.70 (singlet) (ppm), 180.98 (singlet); IR, broad 3500-2800,

Accepted Answer

Question 3

Deduce the identity of the following compound from the spectral data given.
C3H4BrN: 1H NMR, δ 2.98 (2H, triplet), 3.53 (2H, triplet); 13C NMR, δ 21.05 (triplet), 23.87 (triplet), 118.08 (singlet) (ppm); IR, 2963,

Accepted Answer

Question 4

Which compound generates positive peaks for the carbonyl in both its DEPT-90 and DEPT-135 spectra?

Accepted Answer

A)  CH3CH2CHO 
B)  CH3CH2COCH3 
C)  CH3CO2CH2CH3 
D)  CH3CH2CONH2 
E)  H2CO 
A)  CH3CH2CHO 
B)  CH3CH2COCH3 
C)  CH3CO2CH2CH3 
D)  CH3CH2CONH2 
E)  H2CO

Question 5

Deduce the identity of the following compound from the 13C NMR data given.
C4H10O: δ 10.0 (quartet), 22.9 (quartet), 32.0 (triplet), 69.6 (doublet) (ppm)

Accepted Answer

Question 6

Deduce the identity of the following compound from the spectral data given.
C7H10O2: 1H NMR, δ 1.16 (3H, singlet), 2.21 (2H, singlet); 13C NMR, δ 216.25 (singlet), 52.57 (singlet), 34.51 (triplet), 20.22 (quartet) (ppm)

Accepted Answer

2,2-dimeth

Question 7

Using the scale below, draw the 1H NMR spectrum for isobutyl acetate, shown below. Present the peaks with correct splitting patterns and at the approximate chemical shift (+/- 0.5 ppm). Just above each peak, indicate the relative integration value of each type of hydrogen.

Accepted Answer

δ 3.9 ppm (d, 2H), 2

Question 8

The protons marked Ha and Hb in the molecule below are ________.

Accepted Answer

A)  chemically equivalent or homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  endotopic 
E)  none of the above 
A)  chemically equivalent or homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  endotopic 
E)  none of the above

Question 9

Deduce the identity of the following compound from the spectral data given.
C4H8O2: 1H NMR, δ 1.23 (3H, triplet), 2.00 (3H, singlet), 4.02 (2H, quartet) (ppm); IR, 2980,

Accepted Answer

Question 10

How many peaks appear in the proton spin decoupled 13 C NMR spectrum of the compound below?

Accepted Answer

Question 11

Any process faster than ________ will be recorded as an average by NMR spectroscopy.

Accepted Answer

A)  0.0005 seconds 
B)  0.1 seconds 
C)  0.01 seconds 
D)  0.001 seconds 
E)  1 minute 
A)  0.0005 seconds 
B)  0.1 seconds 
C)  0.01 seconds 
D)  0.001 seconds 
E)  1 minute

Question 12

Using a 60-MHz spectrometer, the protons in dichloromethane appear at 5.30 ppm. When the same sample is placed in a 100-MHz instrument, where does the signal appear?

Accepted Answer

A)  8.33 
B)  5.30 
C)  3.18 
D)  cannot be determined from information given 
A)  8.33 
B)  5.30 
C)  3.18 
D)  cannot be determined from information given

Question 13

1H nuclei located near electronegative atoms tend to be ________ relative to 1H nuclei which are not.

Accepted Answer

A)  shielded 
B)  deshielded 
C)  resonanced 
D)  split 
E)  none of the above 
A)  shielded 
B)  deshielded 
C)  resonanced 
D)  split 
E)  none of the above

Question 14

Predict the number of signals expected in the proton spin decoupled 13C NMR spectrum of the compound shown below.

Accepted Answer

Question 15

Deduce the identity of the following compound from the 1H NMR data given.
C8H18O: δ 0.89 (6H, doublet), 1.87 (1H, multiplet), 3.17 (2H, doublet)(ppm)

Accepted Answer

Question 16

Predict the number of signals expected, their splitting, and their relative area in the 1H NMR spectrum of 2-methylpropane (isobutane).

Accepted Answer

2 signals:

Question 17

Predict the number of signals expected in the proton spin decoupled 13C spectrum of cyclopentane.

Accepted Answer

Question 18

Deduce the identity of the following compound from the 1H NMR data given.
C7H7NO3: δ 3.9 (3H, singlet), 6.9 (2H, doublet), 8.1 (2H, doublet) (ppm)

Accepted Answer

p-nitroani

Question 19

Why is carbon-hydrogen splitting not a major part of 1H NMR spectra?

Accepted Answer

Most of the carbons

Question 20

Predict the number of signals expected in the proton spin decoupled 13C spectrum of m-dichlorobenzene (1,3-dichlorobenzene).

Accepted Answer

Exam 13: Nuclear Magnetic Resonance Spectroscopy

Deduce the identity of the following compound from the 13C NMR data given. C4H8O: δ 11.97 (triplet), 33.54 (triplet), 67.03 (doublet) (ppm)

Deduce the identity of the following compound from the spectral data given. C9H10O2: 13C NMR, δ 18.06 (quartet), 45.40 (doublet), 127.32 (doublet), 127.55 (doublet), 128.61 (doublet), 139.70 (singlet) (ppm), 180.98 (singlet); IR, broad 3500-2800,

Deduce the identity of the following compound from the spectral data given. C3H4BrN: 1H NMR, δ 2.98 (2H, triplet), 3.53 (2H, triplet); 13C NMR, δ 21.05 (triplet), 23.87 (triplet), 118.08 (singlet) (ppm); IR, 2963,

Which compound generates positive peaks for the carbonyl in both its DEPT-90 and DEPT-135 spectra?

Deduce the identity of the following compound from the 13C NMR data given. C4H10O: δ 10.0 (quartet), 22.9 (quartet), 32.0 (triplet), 69.6 (doublet) (ppm)

Deduce the identity of the following compound from the spectral data given. C7H10O2: 1H NMR, δ 1.16 (3H, singlet), 2.21 (2H, singlet); 13C NMR, δ 216.25 (singlet), 52.57 (singlet), 34.51 (triplet), 20.22 (quartet) (ppm)

Using the scale below, draw the 1H NMR spectrum for isobutyl acetate, shown below. Present the peaks with correct splitting patterns and at the approximate chemical shift (+/- 0.5 ppm). Just above each peak, indicate the relative integration value of each type of hydrogen.

The protons marked Ha and Hb in the molecule below are ________.

Deduce the identity of the following compound from the spectral data given. C4H8O2: 1H NMR, δ 1.23 (3H, triplet), 2.00 (3H, singlet), 4.02 (2H, quartet) (ppm); IR, 2980,

How many peaks appear in the proton spin decoupled 13 C NMR spectrum of the compound below?

Any process faster than ________ will be recorded as an average by NMR spectroscopy.

Using a 60-MHz spectrometer, the protons in dichloromethane appear at 5.30 ppm. When the same sample is placed in a 100-MHz instrument, where does the signal appear?

1H nuclei located near electronegative atoms tend to be ________ relative to 1H nuclei which are not.

Predict the number of signals expected in the proton spin decoupled 13C NMR spectrum of the compound shown below.

Deduce the identity of the following compound from the 1H NMR data given. C8H18O: δ 0.89 (6H, doublet), 1.87 (1H, multiplet), 3.17 (2H, doublet)(ppm)

Predict the number of signals expected, their splitting, and their relative area in the 1H NMR spectrum of 2-methylpropane (isobutane).

Predict the number of signals expected in the proton spin decoupled 13C spectrum of cyclopentane.

Deduce the identity of the following compound from the 1H NMR data given. C7H7NO3: δ 3.9 (3H, singlet), 6.9 (2H, doublet), 8.1 (2H, doublet) (ppm)

Why is carbon-hydrogen splitting not a major part of 1H NMR spectra?

Predict the number of signals expected in the proton spin decoupled 13C spectrum of m-dichlorobenzene (1,3-dichlorobenzene).

Introduction and Review

Structure and Properties of Organic Molecules

Structure and Stereochemistry of Alkanes

The Study of Chemical Reactions

Stereochemistry

Alkyl Halides: Nucleophilic Substitution and Elimination

Structure and Synthesis of Alkenes

Reactions of Alkenes

Alkynes

Structure and Synthesis of Alcohols

Reactions of Alcohols

Infrared Spectroscopy and Mass Spectrometry

Ethers, Epoxides, and Thioethers

Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy

Aromatic Compounds

Reactions of Aromatic Compounds

Ketones and Aldehydes

Amines

Carboxylic Acids

Carboxylic Acid Derivatives

Condensations and Alpha Substitutions of Carboxyl Compounds

Carbohydrates and Nucleic Acids

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Deduce the identity of the following compound from the ¹³C NMR data given. C₄H₈O: δ 11.97 (triplet), 33.54 (triplet), 67.03 (doublet) (ppm)

Deduce the identity of the following compound from the spectral data given. C₉H₁₀O₂: ¹³C NMR, δ 18.06 (quartet), 45.40 (doublet), 127.32 (doublet), 127.55 (doublet), 128.61 (doublet), 139.70 (singlet) (ppm), 180.98 (singlet); IR, broad 3500-2800,

Deduce the identity of the following compound from the spectral data given. C₃H₄BrN: ¹H NMR, δ 2.98 (2H, triplet), 3.53 (2H, triplet); ¹³C NMR, δ 21.05 (triplet), 23.87 (triplet), 118.08 (singlet) (ppm); IR, 2963,

Deduce the identity of the following compound from the ¹³C NMR data given. C₄H₁₀O: δ 10.0 (quartet), 22.9 (quartet), 32.0 (triplet), 69.6 (doublet) (ppm)

Deduce the identity of the following compound from the spectral data given. C₇H₁₀O₂: ¹H NMR, δ 1.16 (3H, singlet), 2.21 (2H, singlet); ¹³C NMR, δ 216.25 (singlet), 52.57 (singlet), 34.51 (triplet), 20.22 (quartet) (ppm)

Using the scale below, draw the ¹H NMR spectrum for isobutyl acetate, shown below. Present the peaks with correct splitting patterns and at the approximate chemical shift (+/- 0.5 ppm). Just above each peak, indicate the relative integration value of each type of hydrogen.

The protons marked H_a and H_b in the molecule below are ________.

Deduce the identity of the following compound from the spectral data given. C₄H₈O₂: ¹H NMR, δ 1.23 (3H, triplet), 2.00 (3H, singlet), 4.02 (2H, quartet) (ppm); IR, 2980,

How many peaks appear in the proton spin decoupled ¹³C NMR spectrum of the compound below?

¹H nuclei located near electronegative atoms tend to be ________ relative to ¹H nuclei which are not.

Predict the number of signals expected in the proton spin decoupled ¹³C NMR spectrum of the compound shown below.

Deduce the identity of the following compound from the ¹H NMR data given. C₈H₁₈O: δ 0.89 (6H, doublet), 1.87 (1H, multiplet), 3.17 (2H, doublet)(ppm)

Predict the number of signals expected, their splitting, and their relative area in the ¹H NMR spectrum of 2-methylpropane (isobutane).

Predict the number of signals expected in the proton spin decoupled ¹³C spectrum of cyclopentane.

Deduce the identity of the following compound from the ¹H NMR data given. C₇H₇NO₃: δ 3.9 (3H, singlet), 6.9 (2H, doublet), 8.1 (2H, doublet) (ppm)

Why is carbon-hydrogen splitting not a major part of ¹H NMR spectra?

Predict the number of signals expected in the proton spin decoupled ¹³C spectrum of m-dichlorobenzene (1,3-dichlorobenzene).