Question 1

______is used as a reference for recording NMR spectra and is assigned a chemical shift value of zero.

Accepted Answer

Tetramethy

Question 2

The  ADVANCE \u 21 ADVANCE \d 2H NMR spectrum of an alcohol displays a singlet for the OH protons in the range of 2 - 5 ppm. Explain how you can confirm the signal for the OH protons.

Accepted Answer

Acquire the ¹H NMR spectrum for

Question 3

The coupling constant (J) for bromoethane is 7 Hz when the 1H NMR spectrum is acquired at 250 MHz. What is the coupling constant between these protons when the spectrum is acquired at 500 MHz?

Accepted Answer

A)  3.5 Hz 
B)  7 Hz 
C)  14 Hz 
D)  21 Hz 
E)  1 Hz 
A)  3.5 Hz 
B)  7 Hz 
C)  14 Hz 
D)  21 Hz 
E)  1 Hz

Question 4

Determine the multiplicity and predict the chemical shifts of each signal in the expected 1H NMR spectrum of the following compound.

Accepted Answer

Question 5

Which of the following type(s) of protons are chemically non-equivalent?

Accepted Answer

A)  homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  A & B 
E)  B & C 
A)  homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  A & B 
E)  B & C

Question 6

Which of the following type(s) of protons are chemically equivalent?

Accepted Answer

A)  homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  A & B 
E)  B & C 
A)  homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  A & B 
E)  B & C

Question 7

A compound with a molecular formula of C5H10O has the following 1H NMR spectrum. Propose a structure for this compound.

Accepted Answer

Question 8

How many signals would you expect in the 1H NMR spectrum of (CH3)2CHCH2CH2CH3?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 9

Draw a structure, with a formula of C4H10O, which has an integration of 6H, 2H, 1H, and 1H.

Accepted Answer

Question 10

Which of the following is the best prediction of the chemical shifts for the signals in the 1H NMR spectrum for the following compound?

Accepted Answer

A)  I=0.9 ppm, II=2.7 ppm, III=1.2 ppm, IV=0.9 ppm 
B)  I=1.1 ppm, II=3.2 ppm, III=1.4 ppm, IV=0.9 ppm 
C)  I=0.9 ppm, II=1.7 ppm, III=1.2 ppm, IV=1.1 ppm 
D)  I=0.9 ppm, II=1.9 ppm, III=3.4 ppm, IV=0.9 ppm 
E)  none of these 
A)  I=0.9 ppm, II=2.7 ppm, III=1.2 ppm, IV=0.9 ppm 
B)  I=1.1 ppm, II=3.2 ppm, III=1.4 ppm, IV=0.9 ppm 
C)  I=0.9 ppm, II=1.7 ppm, III=1.2 ppm, IV=1.1 ppm 
D)  I=0.9 ppm, II=1.9 ppm, III=3.4 ppm, IV=0.9 ppm 
E)  none of these

Question 11

Which of the following is the best prediction of the chemical shifts for the signals in the 1H NMR spectrum for the following compound?

Accepted Answer

A)  I = 0.9 ppm, II = 1.8 ppm, III = 4.2 ppm, IV = 1.9 ppm 
B)  I = 0.9 ppm, II = 1.2 ppm, III = 3.7 ppm, IV = 1.9 ppm 
C)  I = 0.9 ppm, II = 1.7 ppm, III = 3.4 ppm, IV = 2.4 ppm 
D)  I = 0.9 ppm, II = 1.7 ppm, III = 3.4 ppm, IV = 1.9 ppm 
E)  none of these 
A)  I = 0.9 ppm, II = 1.8 ppm, III = 4.2 ppm, IV = 1.9 ppm 
B)  I = 0.9 ppm, II = 1.2 ppm, III = 3.7 ppm, IV = 1.9 ppm 
C)  I = 0.9 ppm, II = 1.7 ppm, III = 3.4 ppm, IV = 2.4 ppm 
D)  I = 0.9 ppm, II = 1.7 ppm, III = 3.4 ppm, IV = 1.9 ppm 
E)  none of these

Question 12

How many signals would you expect in the 1H NMR spectrum of CH3OCH2CH3?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 13

Propose a structure for a compound, with molecular formula C8H19N, that fits the following spectroscopic data:
IR: 3400 cm-1
1H NMR: 0.9 $\delta$  (triplet, 6H), 1.1 $\delta$  (singlet, 1H, exchanges with D2O), 1.3 $\delta$  (sextet, 4H), 1.4 $\delta$  (quintet, 4H), 2.6 $\delta$  (triplet, 4H)
13C NMR: 13.7, 20.5, 30.4, 49.2

Accepted Answer

The answer of Propose a structure for a compound, with...

Question 14

Protons Ha and Hb in the following compound are _________.

Accepted Answer

A)  homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  mesotopic 
E)  none of these 
A)  homotopic 
B)  enantiotopic 
C)  diastereotopic 
D)  mesotopic 
E)  none of these

Question 15

Which of the following does not display a signal in the DEPT-90, but displays a positive signal in DEPT-135 13C NMR spectroscopy?

Accepted Answer

A)  CH3 
B)  CH2 
C)  CH 
D)  C 
E)  none of these 
A)  CH3 
B)  CH2 
C)  CH 
D)  C 
E)  none of these

Question 16

The broadband decoupling in 13C NMR suppresses ________ splitting.

Accepted Answer

A)  (12C-13
C)  
B)  (12C-1H) 
C)  (13C-13
C)  
D)  (13C-1H) 
E) (none of these) 
A)  (12C-13
C)  
B)  (12C-1H) 
C)  (13C-13
C)  
D)  (13C-1H) 
E) (none of these)

Question 17

Which of the following is true about the location of signals in a 1H NMR spectrum?

Accepted Answer

A)  it indicates the number of neighboring protons 
B)  it indicates the electronic environment of neighboring protons 
C)  it indicates the number of different protons 
D)  it indicates the electronic environment of absorbing protons 
E)  it indicates the number of protons in the signal 
A)  it indicates the number of neighboring protons 
B)  it indicates the electronic environment of neighboring protons 
C)  it indicates the number of different protons 
D)  it indicates the electronic environment of absorbing protons 
E)  it indicates the number of protons in the signal

Question 18

Propose a structure for a compound, with molecular formula C8H14O3, that fits the following spectroscopic data:
IR: 1820cm-1, 1760cm-1
1H NMR: 1.0 $\delta$ (triplet, 6H), 1.6 $\delta$  (sextet, 4H), 2.2 $\delta$  (triplet, 4H)

Accepted Answer

The answer of Propose a structure for a compound, with...

Question 19

A compound, with molecular formula C5H7NO2, displays the following IR, 1H NMR and 13C NMR spectra. Propose a structure for this compound.   
SDBS: National Institute of Advanced Industrial Science and Technology 
 
 SDBS: National Institute of Advanced Industrial Science and Technology

Accepted Answer

Question 20

Which of the following compounds is consistent with the following 13C NMR spectrum?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Exam 15: Nuclear Magnetic Resonance Spectroscopy

______is used as a reference for recording NMR spectra and is assigned a chemical shift value of zero.

The ADVANCE \u 21 ADVANCE \d 2H NMR spectrum of an alcohol displays a singlet for the OH protons in the range of 2 - 5 ppm. Explain how you can confirm the signal for the OH protons.

The coupling constant (J) for bromoethane is 7 Hz when the 1H NMR spectrum is acquired at 250 MHz. What is the coupling constant between these protons when the spectrum is acquired at 500 MHz?

Determine the multiplicity and predict the chemical shifts of each signal in the expected 1H NMR spectrum of the following compound.

Which of the following type(s) of protons are chemically non-equivalent?

Which of the following type(s) of protons are chemically equivalent?

A compound with a molecular formula of C5H10O has the following 1H NMR spectrum. Propose a structure for this compound.

How many signals would you expect in the 1H NMR spectrum of (CH3)2CHCH2CH2CH3?

Draw a structure, with a formula of C4H10O, which has an integration of 6H, 2H, 1H, and 1H.

Which of the following is the best prediction of the chemical shifts for the signals in the 1H NMR spectrum for the following compound?

Which of the following is the best prediction of the chemical shifts for the signals in the 1H NMR spectrum for the following compound?

How many signals would you expect in the 1H NMR spectrum of CH3OCH2CH3?

Protons Ha and Hb in the following compound are _________.

Which of the following does not display a signal in the DEPT-90, but displays a positive signal in DEPT-135 13C NMR spectroscopy?

The broadband decoupling in 13C NMR suppresses ________ splitting.

Which of the following is true about the location of signals in a 1H NMR spectrum?

Propose a structure for a compound, with molecular formula C8H14O3, that fits the following spectroscopic data: IR: 1820cm-1, 1760cm-1 1H NMR: 1.0 δ\deltaδ (triplet, 6H), 1.6 δ\deltaδ (sextet, 4H), 2.2 δ\deltaδ (triplet, 4H)

A compound, with molecular formula C5H7NO2, displays the following IR, 1H NMR and 13C NMR spectra. Propose a structure for this compound. SDBS: National Institute of Advanced Industrial Science and Technology SDBS: National Institute of Advanced Industrial Science and Technology

Which of the following compounds is consistent with the following 13C NMR spectrum?

A Review of General Chemistry: Electrons, Bonds, and Molecular Properties

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereoisomerism

Chemical Reactivity and Mechanisms

Alkyl Halides: Nucleophilic Substitution and Elimination Reactions

Addition Reactions of Alkenes

Alkynes

Radical Reactions

Synthesis

Alcohols and Phenols

Ethers and Epoxides; Thiols and Sulfides

Infrared Spectroscopy and Mass Spectrometry

Conjugated Pi Systems and Pericyclic Reactions

Aromatic Compounds

Aromatic Substitution Reactions

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Alpha Carbon Chemistry: Enols and Enolates

Amines

Introduction to Organometallic Compounds

Carbohydrates

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

The ^{ADVANCE \u 2}¹ ADVANCE \d 2H NMR spectrum of an alcohol displays a singlet for the OH protons in the range of 2 - 5 ppm. Explain how you can confirm the signal for the OH protons.

The coupling constant (J) for bromoethane is 7 Hz when the ¹H NMR spectrum is acquired at 250 MHz. What is the coupling constant between these protons when the spectrum is acquired at 500 MHz?

Determine the multiplicity and predict the chemical shifts of each signal in the expected ¹H NMR spectrum of the following compound.

A compound with a molecular formula of C₅H₁₀O has the following ¹H NMR spectrum. Propose a structure for this compound.

How many signals would you expect in the ¹H NMR spectrum of (CH₃)₂CHCH₂CH₂CH₃?

Draw a structure, with a formula of C₄H₁₀O, which has an integration of 6H, 2H, 1H, and 1H.

Which of the following is the best prediction of the chemical shifts for the signals in the ¹H NMR spectrum for the following compound?

Which of the following is the best prediction of the chemical shifts for the signals in the ¹H NMR spectrum for the following compound?

How many signals would you expect in the ¹H NMR spectrum of CH₃OCH₂CH₃?

Protons H_a and H_b in the following compound are _________.

Which of the following does not display a signal in the DEPT-90, but displays a positive signal in DEPT-135 ¹³C NMR spectroscopy?

The broadband decoupling in ¹³C NMR suppresses ________ splitting.

Which of the following is true about the location of signals in a ¹H NMR spectrum?

Propose a structure for a compound, with molecular formula C₈H₁₄O₃, that fits the following spectroscopic data: IR: 1820cm^-1, 1760cm^-1 ¹H NMR: 1.0 $\delta$ (triplet, 6H), 1.6 $\delta$ (sextet, 4H), 2.2 $\delta$ (triplet, 4H)

A compound, with molecular formula C₅H₇NO₂, displays the following IR, ¹H NMR and ¹³C NMR spectra. Propose a structure for this compound. SDBS: National Institute of Advanced Industrial Science and Technology SDBS: National Institute of Advanced Industrial Science and Technology

Which of the following compounds is consistent with the following ¹³C NMR spectrum?