Question 1

The conjugated portion of the following molecule is circled.

Accepted Answer

A) True 
 B)False  True

Question 2

Which of the following are conjugated dienes?

Accepted Answer

A)  only 1 
B)  only 2 
C)  only 1 and 2 
D)  1, 2 and 3 
A)  only 1 
B)  only 2 
C)  only 1 and 2 
D)  1, 2 and 3 C

Question 3

What are the units of λmax in ultraviolet-visible spectroscopy?

Accepted Answer

A)  J⋅mol−1 
B)  M−1 
C)  nm 
D)  none, λmax is a dimensionless quantity 
A)  J⋅mol−1 
B)  M−1 
C)  nm 
D)  none, λmax is a dimensionless quantity C

Question 4

Which of the following arrangements of p atomic orbitals of 1,3-butadiene has the greatest number of nodes?

Accepted Answer

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

Question 5

What is the IUPAC name of the following compound?

Accepted Answer

A)  (R)-3-vinyl-1-butene 
B)  3-methyl-1,5-pentadiene 
C)  3-methyl-1,4-pentadiene 
D)  (R)-3-methyl-1,4-pentadiene 
A)  (R)-3-vinyl-1-butene 
B)  3-methyl-1,5-pentadiene 
C)  3-methyl-1,4-pentadiene 
D)  (R)-3-methyl-1,4-pentadiene

Question 6

Consider the following structure.   This substance could be produced by the reaction of the following diene and dienophile.

Accepted Answer

A) True 
 B)False

Question 7

Electrophilic addition reaction of conjugated dienes that occur at high temperature and/or long reaction times (reversible conditions) are said to be under kinetic control.

Accepted Answer

A) True 
 B)False

Question 8

What is the correct order of exothermicity for hydrogenation of the following hexadienes upon treatment with H2/Pd (more exothermic > less exothermic)?

Accepted Answer

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

Question 9

Identify the product of the given reaction. ​

Accepted Answer

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

Question 10

The following two compounds could be easily distinguished by NMR, IR, UV or MS spectra.

Accepted Answer

A) True 
 B)False

Question 11

The conjugated portion of the following molecule is circled.

Accepted Answer

A) True 
 B)False

Question 12

What range of wavelengths corresponds to the ultraviolet region of the electromagnetic spectrum?

Accepted Answer

A)  200-400 nm 
B)  400-700 nm 
C)  2.5-25 μm 
D)  2-10 mm 
A)  200-400 nm 
B)  400-700 nm 
C)  2.5-25 μm 
D)  2-10 mm

Question 13

Which of the following arrangements of p atomic orbitals gives the highest energy π-antibonding molecular orbital of 1,3-butadiene?

Accepted Answer

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

Question 14

Which of the following has the highest value of λmax in the ultraviolet-visible spectrum?

Accepted Answer

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

Question 15

What are the units of absorbance, A, in ultraviolet-visible spectroscopy?

Accepted Answer

A)  J⋅mol−1 
B)  nm⋅mol−1 
C)  J⋅mol−1⋅M−1 
D)  none, A is a dimensionless quantity 
A)  J⋅mol−1 
B)  nm⋅mol−1 
C)  J⋅mol−1⋅M−1 
D)  none, A is a dimensionless quantity

Question 16

What is the IUPAC name of the following compound?

Accepted Answer

A)  2,3-dimethyl-2,4-pentadiene 
B)  (Z)-2,3-dimethyl-2,4-pentadiene 
C)  3,4-dimethyl-1,3-pentadiene 
D)  (Z)-3,4-dimethyl-1,3-pentadiene 
A)  2,3-dimethyl-2,4-pentadiene 
B)  (Z)-2,3-dimethyl-2,4-pentadiene 
C)  3,4-dimethyl-1,3-pentadiene 
D)  (Z)-3,4-dimethyl-1,3-pentadiene

Question 17

What is (are) the major organic product(s) formed in the following reaction?

Accepted Answer

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

Question 18

Which of the following is not a major organic product obtained from the addition of 1 mole of bromine to (E)-1,3-pentadiene?

Accepted Answer

A)  (
E) -4,5-dibromo-2-pentene 
B)  3,4-dibromo-1-pentene 
C)  (
E) -1,4-dibromo-2-pentene 
D)  (
E) -1,2-dibromo-2-pentene 
A)  (
E) -4,5-dibromo-2-pentene 
B)  3,4-dibromo-1-pentene 
C)  (
E) -1,4-dibromo-2-pentene 
D)  (
E) -1,2-dibromo-2-pentene

Question 19

What are the two major organic products obtained from the following reaction?

Accepted Answer

The answer of What are the two major organic products...

Question 20

Consider the following spectrum for a conjugated diene.   If a similar spectrum were taken for a conjugated tetraene, the λmax would be _________than 217 nm.

Accepted Answer

Exam 20: Dienes, Conjugated Systems, and Pericyclic Reactions

The conjugated portion of the following molecule is circled.

Which of the following are conjugated dienes?

What are the units of λmax in ultraviolet-visible spectroscopy?

Which of the following arrangements of p atomic orbitals of 1,3-butadiene has the greatest number of nodes?

What is the IUPAC name of the following compound?

Consider the following structure. This substance could be produced by the reaction of the following diene and dienophile.

Electrophilic addition reaction of conjugated dienes that occur at high temperature and/or long reaction times (reversible conditions) are said to be under kinetic control.

What is the correct order of exothermicity for hydrogenation of the following hexadienes upon treatment with H2/Pd (more exothermic > less exothermic)?

Identify the product of the given reaction. ​

The following two compounds could be easily distinguished by NMR, IR, UV or MS spectra.

The conjugated portion of the following molecule is circled.

What range of wavelengths corresponds to the ultraviolet region of the electromagnetic spectrum?

Which of the following arrangements of p atomic orbitals gives the highest energy π-antibonding molecular orbital of 1,3-butadiene?

Which of the following has the highest value of λmax in the ultraviolet-visible spectrum?

What are the units of absorbance, A, in ultraviolet-visible spectroscopy?

What is the IUPAC name of the following compound?

What is (are) the major organic product(s) formed in the following reaction?

Which of the following is not a major organic product obtained from the addition of 1 mole of bromine to (E)-1,3-pentadiene?

What are the two major organic products obtained from the following reaction?

Consider the following spectrum for a conjugated diene. If a similar spectrum were taken for a conjugated tetraene, the λmax would be _________than 217 nm.

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

Nuclear Magnetic Resonance Spectroscopy

Mass Spectrometry

An Introduction to Organometallic Compounds

Aldehydes and Ketones

Carboxylic Acids

Functional Derivatives of Carboxylic Acids

Enolate Anions and Enamines

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

What are the units of λ_max in ultraviolet-visible spectroscopy?

What is the correct order of exothermicity for hydrogenation of the following hexadienes upon treatment with H₂/Pd (more exothermic > less exothermic)?

Identify the product of the given reaction.

Which of the following has the highest value of λ_max in the ultraviolet-visible spectrum?

Consider the following spectrum for a conjugated diene. If a similar spectrum were taken for a conjugated tetraene, the λ_max would be _________than 217 nm.