Question 1

How many peaks would be observed for each of the circled protons in the compounds below?

Accepted Answer

A)  I = 2; II = 6; III = 1. 
B)  I = 3; II = 5; III = 2. 
C)  I = 1; II = 5; III = 1. 
D)  I = 2; II = 6; III = 2. 
A)  I = 2; II = 6; III = 1. 
B)  I = 3; II = 5; III = 2. 
C)  I = 1; II = 5; III = 1. 
D)  I = 2; II = 6; III = 2.

Question 2

Compound X has a molecular formula C8H10, and gives the 1H NMR spectrum below. What is the structure of X?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
A)  A 
B)  B 
C)  C 
D)  D

Question 3

How many different kinds of protons are present in each of the following compounds?

Accepted Answer

A)  I = 6; II = 5; III = 3. 
B)  I = 7; II = 5; III = 3. 
C)  I = 7; II = 6; III = 3. 
D)  I = 6; II = 6; III = 3. 
A)  I = 6; II = 5; III = 3. 
B)  I = 7; II = 5; III = 3. 
C)  I = 7; II = 6; III = 3. 
D)  I = 6; II = 6; III = 3.

Question 4

Which of the following statements is true about electromagnetic radiation?

Accepted Answer

A)  All molecules absorb electromagnetic radiation at some frequency. 
B)  Frequency is directly proportional to wavelength. 
C)  NMR uses the microwave region of the electromagnetic spectrum. 
D)  The radio frequency region of the electromagnetic spectrum has the largest energy per photon. 
E)  Energy is inversely proportional to frequency. 
A)  All molecules absorb electromagnetic radiation at some frequency. 
B)  Frequency is directly proportional to wavelength. 
C)  NMR uses the microwave region of the electromagnetic spectrum. 
D)  The radio frequency region of the electromagnetic spectrum has the largest energy per photon. 
E)  Energy is inversely proportional to frequency.

Question 5

An unknown compound X has the molecular formula C6H14O. Compound X shows a strong peak in its IR spectrum at 3000 cm-1. The 1H NMR spectral data of compound X is given below. What is the structure of compound X?

Accepted Answer

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

Question 6

An unknown compound X has the molecular formula C6H12O2. Compound X shows a strong peak in its IR spectrum at 1700 cm-1. The 1H NMR spectral data of compound X is given below. What is the structure of compound X?

Accepted Answer

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

Question 7

Which of the labeled protons absorbs furthest upfield in the 1H NMR spectrum?

Accepted Answer

A)  HS1U1B1aS1U1B0 
B)  HS1U1B1bS1U1B0 
C)  HS1U1B1cS1U1B0 
D)  HS1U1B1dS1U1B0 
A)  HS1U1B1aS1U1B0 
B)  HS1U1B1bS1U1B0 
C)  HS1U1B1cS1U1B0 
D)  HS1U1B1dS1U1B0

Question 8

Which of the following statements about 13C NMR is not true?

Accepted Answer

A)  "In 13C proton-decoupled NMR spectra, all peaks are singlets." 
B)  "13C NMR spectra display peaks for only carbons that bear hydrogen atoms." 
C)  "13C NMR chemical shifts occur over a greater range than 1H NMR chemical shifts." 
D)  "13C NMR easily differentiates between the different hybridized carbons (sp3, sp2 and sp hybridized carbons)." 
A)  "In 13C proton-decoupled NMR spectra, all peaks are singlets." 
B)  "13C NMR spectra display peaks for only carbons that bear hydrogen atoms." 
C)  "13C NMR chemical shifts occur over a greater range than 1H NMR chemical shifts." 
D)  "13C NMR easily differentiates between the different hybridized carbons (sp3, sp2 and sp hybridized carbons)."

Question 9

Which of the indicated protons absorbs furthest downfield?

Accepted Answer

A)  Ha 
B)  Hb 
C)  Hc 
D)  Hd 
A)  Ha 
B)  Hb 
C)  Hc 
D)  Hd

Question 10

Into how many peaks will each of the circled protons be split?

Accepted Answer

A)  I = 3; II = 7; III = 4. 
B)  I = 2; II = 7; III = 4. 
C)  I = 2; II = 7; III = 3. 
D)  I = 2; II = 6; III = 4. 
A)  I = 3; II = 7; III = 4. 
B)  I = 2; II = 7; III = 4. 
C)  I = 2; II = 7; III = 3. 
D)  I = 2; II = 6; III = 4.

Question 11

An unknown compound X has the molecular formula C6H14O. Compound X shows a peak in its IR spectrum at 3200-3600 cm-1. The 1H NMR spectral data for compound X is given below. What is the structure of compound X?

Accepted Answer

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

Question 12

How many different kinds of protons are present in each of the following molecules?

Accepted Answer

A)  I = 3; II = 5; III = 5; IV = 4; V = 3. 
B)  I = 4; II = 5; III = 4; IV = 4; V = 3. 
C)  I = 4; II = 5; III = 5; IV = 4; V = 3. 
D)  I = 4; II = 5; III = 5; IV = 3; V = 4. 
A)  I = 3; II = 5; III = 5; IV = 4; V = 3. 
B)  I = 4; II = 5; III = 4; IV = 4; V = 3. 
C)  I = 4; II = 5; III = 5; IV = 4; V = 3. 
D)  I = 4; II = 5; III = 5; IV = 3; V = 4.

Question 13

How many different kinds of protons are present in each of the following compounds?

Accepted Answer

A)  I = 2; II = 3; III = 4. 
B)  I = 2; II = 3; III = 3. 
C)  I = 3; II = 3; III = 3. 
D)  I = 3; II = 3; III = 4. 
A)  I = 2; II = 3; III = 4. 
B)  I = 2; II = 3; III = 3. 
C)  I = 3; II = 3; III = 3. 
D)  I = 3; II = 3; III = 4.

Question 14

Which of the following compounds would give rise to a 13C spectrum with 6 peaks?

Accepted Answer

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

Question 15

Into how many peaks will each of the circled protons be split?

Accepted Answer

A)  I = 3; II = 8; III = 1; IV = 4; V = 3. 
B)  I = 9; II = 8; III = 2; IV = 4; V = 4. 
C)  I = 4; II = 8; III = 2; IV = 4; V = 5. 
D)  I = 4; Ii = 7; III = 2; IV = 4; V = 3. 
A)  I = 3; II = 8; III = 1; IV = 4; V = 3. 
B)  I = 9; II = 8; III = 2; IV = 4; V = 4. 
C)  I = 4; II = 8; III = 2; IV = 4; V = 5. 
D)  I = 4; Ii = 7; III = 2; IV = 4; V = 3.

Question 16

For each of the following compounds, indicate how many 13C NMR signals will be observed.

Accepted Answer

A)  a: 4; b: 4; c: 7; d: 4 
B)  a: 5; b: 4; c: 7; d: 3 
C)  a: 4; b: 7; c: 7; d: 3 
D)  a: 5; b: 4; c: 6; d: 5 
A)  a: 4; b: 4; c: 7; d: 4 
B)  a: 5; b: 4; c: 7; d: 3 
C)  a: 4; b: 7; c: 7; d: 3 
D)  a: 5; b: 4; c: 6; d: 5

Question 17

An unknown compound X has the molecular formula C7H13OBr. Compound X shows a strong peak in its IR spectrum at 1700 cm-1. The 1H NMR spectral data of compound X is given below. What is the structure of compound X?

Accepted Answer

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

Question 18

What region of the electromagnetic spectrum does nuclear magnet resonance spectroscopy use?

Accepted Answer

A)  Radio frequency 
B)  Microwave frequency 
C)  Infrared frequency 
D)  Visible frequency 
E)  Ultraviolet frequency 
A)  Radio frequency 
B)  Microwave frequency 
C)  Infrared frequency 
D)  Visible frequency 
E)  Ultraviolet frequency

Question 19

An unknown compound A has the molecular formula C12H16O. Compound A absorbs strongly in the IR at 1700 cm-1. The NMR spectral data for compound A are given below. What is the structure of compound A?

Accepted Answer

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

Question 20

How many peaks would be observed for each of the circled protons in the compounds below?

Accepted Answer

A)  I = 6; II = 2; III = 3. 
B)  I = 7; II = 3; III = 3. 
C)  I = 7; II = 1; III = 3. 
D)  I = 7; II = 2; III = 3. 
A)  I = 6; II = 2; III = 3. 
B)  I = 7; II = 3; III = 3. 
C)  I = 7; II = 1; III = 3. 
D)  I = 7; II = 2; III = 3.

Exam 14: Nuclear Magnetic Resonance Spectroscopy

How many peaks would be observed for each of the circled protons in the compounds below?

Compound X has a molecular formula C8H10, and gives the 1H NMR spectrum below. What is the structure of X?

How many different kinds of protons are present in each of the following compounds?

Which of the following statements is true about electromagnetic radiation?

An unknown compound X has the molecular formula C6H14O. Compound X shows a strong peak in its IR spectrum at 3000 cm-1. The 1H NMR spectral data of compound X is given below. What is the structure of compound X?

An unknown compound X has the molecular formula C6H12O2. Compound X shows a strong peak in its IR spectrum at 1700 cm-1. The 1H NMR spectral data of compound X is given below. What is the structure of compound X?

Which of the labeled protons absorbs furthest upfield in the 1H NMR spectrum?

Which of the following statements about 13C NMR is not true?

Which of the indicated protons absorbs furthest downfield?

Into how many peaks will each of the circled protons be split?

An unknown compound X has the molecular formula C6H14O. Compound X shows a peak in its IR spectrum at 3200-3600 cm-1. The 1H NMR spectral data for compound X is given below. What is the structure of compound X?

How many different kinds of protons are present in each of the following molecules?

How many different kinds of protons are present in each of the following compounds?

Which of the following compounds would give rise to a 13C spectrum with 6 peaks?

Into how many peaks will each of the circled protons be split?

For each of the following compounds, indicate how many 13C NMR signals will be observed.

An unknown compound X has the molecular formula C7H13OBr. Compound X shows a strong peak in its IR spectrum at 1700 cm-1. The 1H NMR spectral data of compound X is given below. What is the structure of compound X?

What region of the electromagnetic spectrum does nuclear magnet resonance spectroscopy use?

An unknown compound A has the molecular formula C12H16O. Compound A absorbs strongly in the IR at 1700 cm-1. The NMR spectral data for compound A are given below. What is the structure of compound A?

How many peaks would be observed for each of the circled protons in the compounds below?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols, Ethers and Epoxides

Alkenes

Alkynes

Oxidation and Reduction

Mass Spectrometry and Infrared Spectroscopy

Radical Reactions

Conjugation, Resonance, and Dienes

Benzene and Aromatic Compounds

Electrophilic Aromatic Substitution

Carboxylic Acids and the Acidity of the O-H Bond

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones Nucleophilic Addition

Carboxylic Acids and Derivatives

Substitution Reactions of Carbonyl Compounds at the Alpha-Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Lipids

Synthetic Polymers

Filters

Compound X has a molecular formula C₈H₁₀, and gives the ¹H NMR spectrum below. What is the structure of X?

An unknown compound X has the molecular formula C₆H₁₄O. Compound X shows a strong peak in its IR spectrum at 3000 cm^-1. The ¹H NMR spectral data of compound X is given below. What is the structure of compound X?

An unknown compound X has the molecular formula C₆H₁₂O₂. Compound X shows a strong peak in its IR spectrum at 1700 cm^-1. The ¹H NMR spectral data of compound X is given below. What is the structure of compound X?

Which of the labeled protons absorbs furthest upfield in the ¹H NMR spectrum?

Which of the following statements about ¹³C NMR is not true?

An unknown compound X has the molecular formula C₆H₁₄O. Compound X shows a peak in its IR spectrum at 3200-3600 cm^-1. The ¹H NMR spectral data for compound X is given below. What is the structure of compound X?

Which of the following compounds would give rise to a ¹³C spectrum with 6 peaks?

For each of the following compounds, indicate how many ¹³C NMR signals will be observed.

An unknown compound X has the molecular formula C₇H₁₃OBr. Compound X shows a strong peak in its IR spectrum at 1700 cm^-1. The ¹H NMR spectral data of compound X is given below. What is the structure of compound X?

An unknown compound A has the molecular formula C₁₂H₁₆O. Compound A absorbs strongly in the IR at 1700 cm^-1. The NMR spectral data for compound A are given below. What is the structure of compound A?