Question 1

Predict the number of signals expected in the proton spin decoupled 13C NMR spectrum of o-diethylbenzene (1,2-diethylbenzene).

Accepted Answer

Question 2

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

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Question 3

On a 90 MHz spectrometer, calculate the frequency at which a proton absorbs if it appears at 4.20 ppm.

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The answer of On a 90 MHz spectrometer, calculate the...

Question 4

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

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Question 5

A nucleus with an ________ atomic number or an ________ mass number has a nuclear spin that can be observed by the NMR spectrometer.

Accepted Answer

A)   even; odd
B)   odd; even
C)   odd; odd
D)   even; even

Question 6

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

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Question 7

Use the structure below to state the relationship between the indicated protons as equivalent, enantiotopic, diastereotopic, or unrelated.  
Ha & Hb:
Ha & Hc:
Hb & Hc:

Accepted Answer

H_a & H_b: Diastereotopi...

Question 8

What information does the intensity (integration)  of a signal in the 1H NMR spectrum give you?

Accepted Answer

A)   how many different types of protons are present
B)   the electronic structure of the molecule close to each type of proton
C)   how many protons of each type are present
D)   how many neighboring protons are present

Question 9

An NMR spectrometer that operates at a frequency of 60 MHz for 13C NMR spectra, operates at what frequency for 1H NMR spectra?

Accepted Answer

A)   15 MHz
B)   30 MHz
C)   60 MHz
D)   120 MHz
E)   240 MHz

Question 10

Describe the number of signals and their splitting in the 1H NMR spectrum of (CH3) 2CHOCH3.

Accepted Answer

A)   3 signals: 2 doublets and a septet
B)   2 signals: a doublet and a septet
C)   3 signals: a doublet, a quartet, and a septet
D)   4 signals: 2 doublets, a singlet, and a septet
E)   3 signals: a singlet, a doublet, and a septet

Question 11

The 1H NMR spectrum of ethanol is acquired and the hydroxyl signal appears as a singlet instead of a triplet. Offer an explanation.

Accepted Answer

A fast exchange of the hydroxy...

Question 12

Why is carbon-carbon splitting typically not seen in 13C NMR spectra?

Accepted Answer

Only 1% of the carbo...

Question 13

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

Accepted Answer

Most of the carbons ...

Question 14

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

Accepted Answer

Question 15

What 1H NMR spectral data is expected for the compound shown? 1H NMR spectral data is expected for the compound shown?   A)  3.8 (1H, septet) , 2.1 (3H, s) , 1.0 (6H, d)  B)  3.8 (1H, septet) , 3.3 (3H, s) , 1.0 (6H, d)  C)  3.3 (3H, s) , 2.6 (3H, septet) , 1.0 (6H, d)  D)  2.6 (1H, septet) , 2.1 (3H, s) , 1.0 (6H, d) " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   3.8 (1H, septet) , 2.1 (3H, s) , 1.0 (6H, d) 
B)   3.8 (1H, septet) , 3.3 (3H, s) , 1.0 (6H, d) 
C)   3.3 (3H, s) , 2.6 (3H, septet) , 1.0 (6H, d) 
D)   2.6 (1H, septet) , 2.1 (3H, s) , 1.0 (6H, d)

Question 16

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

Accepted Answer

Question 17

What three-word term is abbreviated NMR?

Accepted Answer

nuclear ma...

Question 18

You have a sample and its 1H NMR spectrum. You know your sample contains O atoms but not N atoms, and you suspect that your sample may be an alcohol. What common spectroscopic technique might you use to confirm your suspicion?

Accepted Answer

Take an IR spectrum and look f...

Question 19

Deduce the identity of the following compound from the spectral data given.
C8H10: 1H NMR, δ 1.20 (3H, triplet), 2.60 (2H, quartet), 7.12 (5H, singlet) (ppm); IR, 3050, 2970,  
MS, m/z 91

Accepted Answer

Question 20

Provide a structure that is consistent with the data below.
C7H14O2
IR (cm-1): 2950, 1740
1H NMR ( d): 2.3 (2H, q), 1.0 (3H, t), 0.9 (9H, s)
13C NMR (d ): 185 (s), 78 (s), 29 (t), 14 (q), 12 (q)

Accepted Answer

Exam 13: Nuclear Magnetic Resonance Spectroscopy

A nucleus with an ________ atomic number or an ________ mass number has a nuclear spin that can be observed by the NMR spectrometer.

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An NMR spectrometer that operates at a frequency of 60 MHz for 13C NMR spectra, operates at what frequency for 1H NMR spectra?

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Why is carbon-carbon splitting typically not seen in 13C NMR spectra?

Correct AnswerverifiedOnly 1% of the carbo...View AnswerShow Answer

Deduce the identity of the following compound from the spectral data given. C8H10: 1H NMR, δ 1.20 (3H, triplet), 2.60 (2H, quartet), 7.12 (5H, singlet) (ppm); IR, 3050, 2970, MS, m/z 91

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

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Predict the number of signals expected in the proton spin decoupled 13C NMR spectrum of o-diethylbenzene (1,2-diethylbenzene).

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Provide a structure that is consistent with the data below. C7H14O2 IR (cm-1): 2950, 1740 1H NMR ( d): 2.3 (2H, q), 1.0 (3H, t), 0.9 (9H, s) 13C NMR (d ): 185 (s), 78 (s), 29 (t), 14 (q), 12 (q)

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What 1H NMR spectral data is expected for the compound shown?

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

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

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What information does the intensity (integration) of a signal in the 1H NMR spectrum give you?

Correct AnswerverifiedShow Answer

The 1H NMR spectrum of ethanol is acquired and the hydroxyl signal appears as a singlet instead of a triplet. Offer an explanation.

Correct AnswerverifiedA fast exchange of the hydroxy...View AnswerShow Answer

What three-word term is abbreviated NMR?

Correct Answerverifiednuclear ma...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

On a 90 MHz spectrometer, calculate the frequency at which a proton absorbs if it appears at 4.20 ppm.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedMost of the carbons ...View AnswerShow Answer

Use the structure below to state the relationship between the indicated protons as equivalent, enantiotopic, diastereotopic, or unrelated. Ha & Hb: Ha & Hc: Hb & Hc:

Correct AnswerverifiedHa & Hb: Diastereotopi...View AnswerShow Answer

You have a sample and its 1H NMR spectrum. You know your sample contains O atoms but not N atoms, and you suspect that your sample may be an alcohol. What common spectroscopic technique might you use to confirm your suspicion?

Correct AnswerverifiedTake an IR spectrum and look f...View AnswerShow Answer

Describe the number of signals and their splitting in the 1H NMR spectrum of (CH3) 2CHOCH3.

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A nucleus with an atomic number or an mass number has a nuclear spin that can be observed by the NMR spectrometer.

Correct Answer
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An NMR spectrometer that operates at a frequency of 60 MHz for ¹³C NMR spectra, operates at what frequency for ¹H NMR spectra?

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Why is carbon-carbon splitting typically not seen in ¹³C NMR spectra?

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Only 1% of the carbo...
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Deduce the identity of the following compound from the spectral data given. C₈H₁₀: ¹H NMR, δ 1.20 (3H, triplet), 2.60 (2H, quartet), 7.12 (5H, singlet) (ppm); IR, 3050, 2970, MS, m/z 91

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

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Predict the number of signals expected in the proton spin decoupled ¹³C NMR spectrum of o-diethylbenzene (1,2-diethylbenzene).

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Provide a structure that is consistent with the data below. C₇H₁₄O₂ IR (cm^-1): 2950, 1740 ¹H NMR ( d): 2.3 (2H, q), 1.0 (3H, t), 0.9 (9H, s) ¹³C NMR (d ): 185 (s), 78 (s), 29 (t), 14 (q), 12 (q)

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What ¹H NMR spectral data is expected for the compound shown?

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

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

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What information does the intensity (integration) of a signal in the ¹H NMR spectrum give you?

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The ¹H NMR spectrum of ethanol is acquired and the hydroxyl signal appears as a singlet instead of a triplet. Offer an explanation.

Correct Answer
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A fast exchange of the hydroxy...
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nuclear ma...
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How many peaks appear in the proton spin decoupled ¹³C NMR spectrum of the compound below?

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

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

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Most of the carbons ...
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Use the structure below to state the relationship between the indicated protons as equivalent, enantiotopic, diastereotopic, or unrelated. H_a & H_b: H_a & H_c: H_b & H_c:

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H_a & H_b: Diastereotopi...
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You have a sample and its ¹H NMR spectrum. You know your sample contains O atoms but not N atoms, and you suspect that your sample may be an alcohol. What common spectroscopic technique might you use to confirm your suspicion?

Correct Answer
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Take an IR spectrum and look f...
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Describe the number of signals and their splitting in the ¹H NMR spectrum of (CH₃) ₂CHOCH₃.

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