Question 1

Identify the compound (C4H8O) that gives the following 1H NMR spectrum.

Accepted Answer

Question 2

How many signals appear in proton-decoupled 13C NMR spectrum of 2,5-dimethylhexane?

Accepted Answer

A)  3 
B)  4 
C)  5 
D)  6 
A)  3 
B)  4 
C)  5 
D)  6

Question 3

Which of the protons in the following molecule appear at the highest ?-value in the 1H NMR spectrum? $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$O
$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$||
$\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{CH}_{2}-\mathrm{C}-\mathrm{H}$
$\quad$i $\quad$$\quad$$\quad$ii $\quad$$\quad$iii$\quad$$\quad$$\quad$ iv

Accepted Answer

A)  i 
B)  ii 
C)  iii 
D)  iv 
A)  i 
B)  ii 
C)  iii 
D)  iv

Question 4

For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband hydrogen-decoupled S1U1P113S1S1P0C NMR spectra. Enter the numerical value in the blank provided to the left of the structure.
-_______

Accepted Answer

The answer of For each of the compounds below tell...

Question 5

Identify the compound (C4H6O2) that gives the following 1H NMR spectrum.

Accepted Answer

methyl pro

Question 6

Identify the compound (C3H7Cl) that gives the following 1H NMR spectrum.

Accepted Answer

Question 7

The chemical shift of the protons of acetone, CH3COCH3, is 2.1 ppm when the spectrum is obtained at 250 MHz. What is the chemical shift of these protons when the spectrum is acquired at 500 MHz?

Accepted Answer

A)  1.05 ppm 
B)  2.1 ppm 
C)  4.2 ppm 
D)  8.4 ppm 
A)  1.05 ppm 
B)  2.1 ppm 
C)  4.2 ppm 
D)  8.4 ppm

Question 8

Identify the methyl hydrogen with the highest chemical shift.

Accepted Answer

A) 
$\mathrm{H}_{3} \mathrm{C} - \mathrm{F}$ 
B) 
$\mathrm{H}_{3} \mathrm{C}-\mathrm{Cl}$ 
C) 
$\mathrm{H}_{3} \mathrm{C}-\mathrm{Br}$ 
D) 
$\mathrm{H}_{3} \mathrm{C}-\text { | }$ 
A) 
$\mathrm{H}_{3} \mathrm{C} - \mathrm{F}$ 
B) 
$\mathrm{H}_{3} \mathrm{C}-\mathrm{Cl}$ 
C) 
$\mathrm{H}_{3} \mathrm{C}-\mathrm{Br}$ 
D) 
$\mathrm{H}_{3} \mathrm{C}-\text { | }$

Question 9

How many signals appear in proton-decoupled 13C NMR spectrum of 3,4-dimethylhexane?

Accepted Answer

A)  3 
B)  4 
C)  5 
D)  6 
A)  3 
B)  4 
C)  5 
D)  6

Question 10

Which of the carbon atoms in the molecule appears furthest downfield in the 13C NMR spectrum?

Accepted Answer

A)  i 
B)  ii 
C)  iii 
D)  iv 
A)  i 
B)  ii 
C)  iii 
D)  iv

Question 11

The coupling constant, J, between the protons of chloroethane is 7 Hz when the spectrum is obtained 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 
A)  3.5 Hz 
B)  7 Hz 
C)  14 Hz 
D)  21 Hz

Question 12

What does "Y" denote in the coupling parameter xJy?

Accepted Answer

A)  Number of bonds involved in coupling 
B)  Homonuclear or heteronuclear interaction 
C)  Short-range coupling parameter 
D)  Karplus empirical formula 
A)  Number of bonds involved in coupling 
B)  Homonuclear or heteronuclear interaction 
C)  Short-range coupling parameter 
D)  Karplus empirical formula

Question 13

Which of the following compounds gives a 1H NMR spectrum consisting of only a singlet?

Accepted Answer

A)  1,1-dibromopropane 
B)  1,2-dibromopropane 
C)  1,3-dibromopropane 
D)  2,2-dibromopropane 
A)  1,1-dibromopropane 
B)  1,2-dibromopropane 
C)  1,3-dibromopropane 
D)  2,2-dibromopropane

Question 14

Which C4H9Br compound gives a triplet at approximately 3.5 ppm in the 1H NMR spectrum?

Accepted Answer

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

Question 15

How many signals appear in the proton-decoupled 13C NMR spectrum of 4-bromotoluene?

Accepted Answer

A)  3 
B)  4 
C)  5 
D)  7 
A)  3 
B)  4 
C)  5 
D)  7

Question 16

How many types of equivalent hydrogens are present in the following compound? ​

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
A)  0 
B)  1 
C)  2 
D)  3

Question 17

How many signals appear in the proton-decoupled 13C NMR spectrum of 1,2-dibromobenzene?

Accepted Answer

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

Question 18

Which feature in the 1H NMR spectrum provides information about the number of neighboring protons of each proton in the compound?

Accepted Answer

A)  number of signals 
B)  integral 
C)  multiplicity 
D)  chemical shift 
A)  number of signals 
B)  integral 
C)  multiplicity 
D)  chemical shift

Question 19

How many signals appear in the proton-decoupled 13C NMR spectrum of 3-bromotoluene?

Accepted Answer

A)  3 
B)  4 
C)  5 
D)  7 
A)  3 
B)  4 
C)  5 
D)  7

Exam 13: Nuclear Magnetic Resonance Spectroscopy

Identify the compound (C4H8O) that gives the following 1H NMR spectrum.

How many signals appear in proton-decoupled 13C NMR spectrum of 2,5-dimethylhexane?

For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband hydrogen-decoupled 13C NMR spectra. Enter the numerical value in the blank provided to the left of the structure. -_______

Identify the compound (C4H6O2) that gives the following 1H NMR spectrum.

Identify the compound (C3H7Cl) that gives the following 1H NMR spectrum.

The chemical shift of the protons of acetone, CH3COCH3, is 2.1 ppm when the spectrum is obtained at 250 MHz. What is the chemical shift of these protons when the spectrum is acquired at 500 MHz?

Identify the methyl hydrogen with the highest chemical shift.

How many signals appear in proton-decoupled 13C NMR spectrum of 3,4-dimethylhexane?

Which of the carbon atoms in the molecule appears furthest downfield in the 13C NMR spectrum?

The coupling constant, J, between the protons of chloroethane is 7 Hz when the spectrum is obtained at 250 MHz. What is the coupling constant between these protons when the spectrum is acquired at 500 MHz?

What does "Y" denote in the coupling parameter xJy?

Which of the following compounds gives a 1H NMR spectrum consisting of only a singlet?

Which C4H9Br compound gives a triplet at approximately 3.5 ppm in the 1H NMR spectrum?

How many signals appear in the proton-decoupled 13C NMR spectrum of 4-bromotoluene?

How many types of equivalent hydrogens are present in the following compound? ​

How many signals appear in the proton-decoupled 13C NMR spectrum of 1,2-dibromobenzene?

Which feature in the 1H NMR spectrum provides information about the number of neighboring protons of each proton in the compound?

How many signals appear in the proton-decoupled 13C NMR spectrum of 3-bromotoluene?

Covalent Bonding and Shapes of Molecules

Alkanes and Cycloalkanes

Stereoisomerism and Chirality

Acids and Bases

Alkenes: Bonding, Nomenclature, and Properties

Reactions of Alkenes

Alkynes

Haloalkanes, Halogenation, and Radical Reactions

Nucleophilic Substitution and Beta-Elimination

Alcohols

Ethers, Epoxides, and Sulfides

Infrared Spectroscopy

Mass Spectrometry

An Introduction to Organometallic Compounds

Aldehydes and Ketones

Carboxylic Acids

Functional Derivatives of Carboxylic Acids

Enolate Anions and Enamines

Dienes, Conjugated Systems, and Pericyclic Reactions

Benzene and the Concept of Aromaticity

Reactions of Benzene and Its Derivatives

Amines

Catalytic Carbon-Carbon Bond Formation

Carbohydrates

Lipids

Amino Acids and Proteins

Nucleic Acids

Organic Polymer Chemistry

Filters

Identify the compound (C₄H₈O) that gives the following ¹H NMR spectrum.

How many signals appear in proton-decoupled ¹³C NMR spectrum of 2,5-dimethylhexane?

For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband hydrogen-decoupled ¹³C NMR spectra. Enter the numerical value in the blank provided to the left of the structure. -_______

Identify the compound (C₄H₆O₂) that gives the following ¹H NMR spectrum.

Identify the compound (C₃H₇Cl) that gives the following ¹H NMR spectrum.

The chemical shift of the protons of acetone, CH₃COCH₃, is 2.1 ppm when the spectrum is obtained at 250 MHz. What is the chemical shift of these protons when the spectrum is acquired at 500 MHz?

How many signals appear in proton-decoupled ¹³C NMR spectrum of 3,4-dimethylhexane?

Which of the carbon atoms in the molecule appears furthest downfield in the ¹³C NMR spectrum?

What does "Y" denote in the coupling parameter ^xJ_y?

Which of the following compounds gives a ¹H NMR spectrum consisting of only a singlet?

Which C₄H₉Br compound gives a triplet at approximately 3.5 ppm in the ¹H NMR spectrum?

How many signals appear in the proton-decoupled ¹³C NMR spectrum of 4-bromotoluene?

How many types of equivalent hydrogens are present in the following compound?

How many signals appear in the proton-decoupled ¹³C NMR spectrum of 1,2-dibromobenzene?

Which feature in the ¹H NMR spectrum provides information about the number of neighboring protons of each proton in the compound?

How many signals appear in the proton-decoupled ¹³C NMR spectrum of 3-bromotoluene?