Question 1

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 2

Into how many peaks will each of the circled protons be split? (Assume complete resolution of all NMR peaks is possible)

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 3

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 4

How could spectroscopy be used to distinguish between the following compounds?

Accepted Answer

A) Compound A has a triplet in its 1H NMR spectrum at 1.0 ppm. 
B) Compound B has a peak at 3200-3500 cm-1 in its IR spectrum. 
C) Compound A has a peak in its IR spectrum at 2900 cm-1. 
D) Compound A has a triplet in its 1H NMR spectrum at 1.0 ppm and compound B has a peak at 3200-3500 cm-1 in its IR spectrum. 
A) Compound A has a triplet in its 1H NMR spectrum at 1.0 ppm. 
B) Compound B has a peak at 3200-3500 cm-1 in its IR spectrum. 
C) Compound A has a peak in its IR spectrum at 2900 cm-1. 
D) Compound A has a triplet in its 1H NMR spectrum at 1.0 ppm and compound B has a peak at 3200-3500 cm-1 in its IR spectrum.

Question 5

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

Accepted Answer

A) I = 6; II = 3; III = 4 
B) I = 5; II = 3; III = 4 
C) I = 6; II = 4; III = 5 
D) I = 6; II = 4; III = 4 
A) I = 6; II = 3; III = 4 
B) I = 5; II = 3; III = 4 
C) I = 6; II = 4; III = 5 
D) I = 6; II = 4; III = 4

Question 6

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 7

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

Question 8

What effect does increasing the operating frequency of a 1H NMR spectrum have on the magnitude of a coupling constant J in Hz?

Accepted Answer

A) Magnitude of coupling constant J in Hz will also increase. 
B) Magnitude of coupling constant J in Hz will decrease. 
C) Magnitude of coupling constant J in Hz will remain the same. 
D) It is not possible to predict the change in the magnitude of coupling constant J in Hz. 
A) Magnitude of coupling constant J in Hz will also increase. 
B) Magnitude of coupling constant J in Hz will decrease. 
C) Magnitude of coupling constant J in Hz will remain the same. 
D) It is not possible to predict the change in the magnitude of coupling constant J in Hz.

Question 9

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

Accepted Answer

A) I = 6; II = 3; III = 6 
B) I = 5; II = 4; III = 6 
C) I = 6,II = 4,III = 4 
D) I = 6; II = 4; III = 6 
A) I = 6; II = 3; III = 6 
B) I = 5; II = 4; III = 6 
C) I = 6,II = 4,III = 4 
D) I = 6; II = 4; III = 6

Question 10

How many different kinds of 13C peaks will be seen?

Accepted Answer

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

Question 11

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

Exam 32: Spectroscopy C: Nuclear Magnetic Resonance Spectroscopy

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? (Assume complete resolution of all NMR peaks is possible)

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

How could spectroscopy be used to distinguish between the following compounds?

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

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

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

What effect does increasing the operating frequency of a 1H NMR spectrum have on the magnitude of a coupling constant J in Hz?

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

How many different kinds of 13C peaks will be seen?

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?

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 Related Compounds

Alkenes and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Radical Reactions

Conjugation,resonance,and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Spectroscopy A: Mass Spectrometry

Spectroscopy B: Infrared Spectroscopy

Filters

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

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

What effect does increasing the operating frequency of a ¹H NMR spectrum have on the magnitude of a coupling constant J in Hz?

How many different kinds of ¹³C peaks will be seen?

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?