Question 1

Which carbon signal is furthest down field in a proton spin decoupled 13C NMR spectrum?

Accepted Answer

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

Question 2

Predict the number of signals expected (disregarding splitting) in the 1H NMR spectrum of the compound shown below.

Accepted Answer

Question 3

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 4

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

Accepted Answer

Question 5

The chair form of cyclohexane has protons in two distinct environments, axial and equatorial. When the proton NMR of cyclohexane is run on a 100-MHz instrument at 23°C, only one signal for the compound is observed. Explain this apparent contradiction.

Accepted Answer

Axial and equatorial positions are being

Question 6

If a signal is observed in the 170 to 200 ppm range in a 13C NMR spectrum, what is the most likely type of functional group associated with that carbon atom?

Accepted Answer

A)  carbonyl carbon 
B)  allylic carbon 
C)  aromatic carbon 
D)  carbon/carbon triple bond 
E)  carbon/carbon double bond 
A)  carbonyl carbon 
B)  allylic carbon 
C)  aromatic carbon 
D)  carbon/carbon triple bond 
E)  carbon/carbon double bond

Question 7

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 8

Deduce the identity of the following compound from the 1H NMR data given.
C4H7BrO: δ 2.2 (3H, singlet), 3.5 (2H, triplet), 4.5 (2H, triplet) (ppm)

Accepted Answer

Question 9

Deduce the identity of the following compound from the 1H NMR data given.
C5H12O: δ 1.0 (3H, triplet), 1.2-1.8 (6H, multiplet), 3.0 (1H, broad singlet), 3.8 (2H, triplet) (ppm)

Accepted Answer

Question 10

Predict the number of signals expected (disregarding splitting) in the 1H spectrum of o-chlorophenol (2-chlorophenol).

Accepted Answer

Question 11

Draw the 1H NMR spectrum for the following compound.

Accepted Answer

Question 12

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 13

Provide a structure that is consistent with the data below.
C5H10O
IR (cm-1): 2950, 1720
1H NMR ( d): 2.6 (1H, septet), 2.1 (3H, s), 1.0 (6H, d)
13C NMR (d ): 195 (s), 42 (d), 18 (q), 11 (q)

Accepted Answer

Question 14

Predict the number of signals expected in the proton spin decoupled 13C spectrum of   
(1,4-dibromobenzene).

Accepted Answer

Question 15

Deduce the identity of the compound whose molecular formula is C8H14 from the spectral data provided: IR (cm-1): 2950, 2180; 1H NMR (δ): 0.9 (3H, t), 1.0 (9H, s), 2.3 (2H, q) (ppm).

Accepted Answer

2,2-dimeth

Question 16

Provide a structure that is consistent with the data below.
C4H11N
IR (cm-1): 3370 (medium), 3300 (medium), 2950
1H NMR ( d): 2.8 (2H, t), 1.5 (2H, s), 1.4 (1H, m), 0.9 (6H, d)
13C NMR (d ): 50 (t), 31 (d), 20 (q)
MS (m/z): 30, 73

Accepted Answer

Question 17

Compound I has a molecular formula of C7H16. In 13C NMR, compound I gave 3 peaks and in 1H NMR it also gave 3 peaks, a doublet, a triplet and a multiplet. Provide a structure for compound I.

Accepted Answer

Question 18

Predict the number of signals expected in the proton spin decoupled 13C NMR spectrum of p-diethylbenzene (1,4-diethylbenzene).

Accepted Answer

Question 19

A peak split into a doublet of triplets gave the following measurements in its splitting pattern. State the coupling constants (J values) for both the doublet and the triplet.

Accepted Answer

doublet: J

Question 20

What is the approximate chemical shift of an alkynyl carbon in 13C NMR spectroscopy?

Accepted Answer

A)  10 ppm 
B)  30 ppm 
C)  70 ppm 
D)  120 ppm 
E)  200 ppm 
A)  10 ppm 
B)  30 ppm 
C)  70 ppm 
D)  120 ppm 
E)  200 ppm

Exam 13: Nuclear Magnetic Resonance Spectroscopy

Which carbon signal is furthest down field in a proton spin decoupled 13C NMR spectrum?

Predict the number of signals expected (disregarding splitting) in the 1H 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 in the proton spin decoupled 13C spectrum of cyclopentane.

The chair form of cyclohexane has protons in two distinct environments, axial and equatorial. When the proton NMR of cyclohexane is run on a 100-MHz instrument at 23°C, only one signal for the compound is observed. Explain this apparent contradiction.

If a signal is observed in the 170 to 200 ppm range in a 13C NMR spectrum, what is the most likely type of functional group associated with that carbon atom?

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?

Deduce the identity of the following compound from the 1H NMR data given. C4H7BrO: δ 2.2 (3H, singlet), 3.5 (2H, triplet), 4.5 (2H, triplet) (ppm)

Deduce the identity of the following compound from the 1H NMR data given. C5H12O: δ 1.0 (3H, triplet), 1.2-1.8 (6H, multiplet), 3.0 (1H, broad singlet), 3.8 (2H, triplet) (ppm)

Predict the number of signals expected (disregarding splitting) in the 1H spectrum of o-chlorophenol (2-chlorophenol).

Draw the 1H NMR spectrum for the following compound.

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,

Provide a structure that is consistent with the data below. C5H10O IR (cm-1): 2950, 1720 1H NMR ( d): 2.6 (1H, septet), 2.1 (3H, s), 1.0 (6H, d) 13C NMR (d ): 195 (s), 42 (d), 18 (q), 11 (q)

Predict the number of signals expected in the proton spin decoupled 13C spectrum of (1,4-dibromobenzene).

Deduce the identity of the compound whose molecular formula is C8H14 from the spectral data provided: IR (cm-1): 2950, 2180; 1H NMR (δ): 0.9 (3H, t), 1.0 (9H, s), 2.3 (2H, q) (ppm).

Provide a structure that is consistent with the data below. C4H11N IR (cm-1): 3370 (medium), 3300 (medium), 2950 1H NMR ( d): 2.8 (2H, t), 1.5 (2H, s), 1.4 (1H, m), 0.9 (6H, d) 13C NMR (d ): 50 (t), 31 (d), 20 (q) MS (m/z): 30, 73

Compound I has a molecular formula of C7H16. In 13C NMR, compound I gave 3 peaks and in 1H NMR it also gave 3 peaks, a doublet, a triplet and a multiplet. Provide a structure for compound I.

Predict the number of signals expected in the proton spin decoupled 13C NMR spectrum of p-diethylbenzene (1,4-diethylbenzene).

A peak split into a doublet of triplets gave the following measurements in its splitting pattern. State the coupling constants (J values) for both the doublet and the triplet.

What is the approximate chemical shift of an alkynyl carbon in 13C NMR spectroscopy?

Structure and Bonding

Acids and Bases; Functional Groups

Structure and Stereochemistry of Alkanes

The Study of Chemical Reactions

Stereochemistry

Alkyl Halides; Nucleophilic Substitution

Structure and Synthesis of Alkenes; Elimination

Reactions of Alkenes

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

Which carbon signal is furthest down field in a proton spin decoupled ¹³C NMR spectrum?

Predict the number of signals expected (disregarding splitting) in the ¹H 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 in the proton spin decoupled ¹³C spectrum of cyclopentane.

If a signal is observed in the 170 to 200 ppm range in a ¹³C NMR spectrum, what is the most likely type of functional group associated with that carbon atom?

Deduce the identity of the following compound from the ¹H NMR data given. C₄H₇BrO: δ 2.2 (3H, singlet), 3.5 (2H, triplet), 4.5 (2H, triplet) (ppm)

Deduce the identity of the following compound from the ¹H NMR data given. C₅H₁₂O: δ 1.0 (3H, triplet), 1.2-1.8 (6H, multiplet), 3.0 (1H, broad singlet), 3.8 (2H, triplet) (ppm)

Predict the number of signals expected (disregarding splitting) in the ¹H spectrum of o-chlorophenol (2-chlorophenol).

Draw the ¹H NMR spectrum for the following compound.

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,

Provide a structure that is consistent with the data below. C₅H₁₀O IR (cm^-1): 2950, 1720 ¹H NMR ( d): 2.6 (1H, septet), 2.1 (3H, s), 1.0 (6H, d) ¹³C NMR (d ): 195 (s), 42 (d), 18 (q), 11 (q)

Predict the number of signals expected in the proton spin decoupled ¹³C spectrum of (1,4-dibromobenzene).

Deduce the identity of the compound whose molecular formula is C₈H₁₄ from the spectral data provided: IR (cm^-1): 2950, 2180; ¹H NMR (δ): 0.9 (3H, t), 1.0 (9H, s), 2.3 (2H, q) (ppm).

Provide a structure that is consistent with the data below. C₄H₁₁N IR (cm^-1): 3370 (medium), 3300 (medium), 2950 ¹H NMR ( d): 2.8 (2H, t), 1.5 (2H, s), 1.4 (1H, m), 0.9 (6H, d) ¹³C NMR (d ): 50 (t), 31 (d), 20 (q) MS (m/z): 30, 73

Compound I has a molecular formula of C₇H₁₆. In ¹³C NMR, compound I gave 3 peaks and in ¹H NMR it also gave 3 peaks, a doublet, a triplet and a multiplet. Provide a structure for compound I.

Predict the number of signals expected in the proton spin decoupled ¹³C NMR spectrum of p-diethylbenzene (1,4-diethylbenzene).

What is the approximate chemical shift of an alkynyl carbon in ¹³C NMR spectroscopy?