Question 1

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 2

Which of the following has the highest value of λmax in the ultraviolet-visible spectrum? max in the ultraviolet-visible spectrum?   A)  1 B)  2 C)  3 D)  4" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   1
B)   2
C)   3
D)   4E) B) and D)
F) B) and C)

Question 3

What is the correct order of exothermicity for hydrogenation of the following hexadienes upon treatment with H2/Pd (more exothermic > less exothermic) ? 2/Pd (more exothermic > less exothermic) ?   A)  1 > 2 > 3 B)  3 > 1 > 2 C)  2 > 1 > 3 D)  3 > 2 > 1" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   1 > 2 > 3
B)   3 > 1 > 2
C)   2 > 1 > 3
D)   3 > 2 > 1E) B) and D)
F) B) and C)

Question 4

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 5

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

Question 6

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 7

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 mmE) A) and B)
F) A) and C)

Question 8

Which of the following are conjugated dienes?

Accepted Answer

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

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

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-pentadieneE) B) and D)
F) C) and D)

Question 11

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-pentadieneE) B) and C)
F) A) and D)

Question 12

Identify the product of the given reaction. ​

Accepted Answer

A)   I
B)   II
C)   IV
D)   IIIE) A) and C)
F) B) and C)

Question 13

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-penteneE) A) and B)
F) B) and C)

Question 14

The conjugated portion of the following molecule is circled.

Accepted Answer

A) True 
 B)False  True

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 quantityE) None of the above
F) A) and D)

Question 16

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 4E) None of the above
F) All of the above

Question 17

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)   4E) C) and D)
F) B) and C)

Question 18

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)   4E) B) and D)
F) A) and B)

Question 19

The conjugated portion of the following molecule is circled.

Accepted Answer

A) True 
 B)False

Question 20

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 quantityE) All of the above
F) B) and C) C

Exam 20: Dienes, Conjugated Systems, and Pericyclic Reactions

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.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following are conjugated dienes?

Correct AnswerverifiedC

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

Correct AnswerverifiedShow Answer

What is the IUPAC name of the following compound?

Correct AnswerverifiedShow Answer

What is the IUPAC name of the following compound?

Correct AnswerverifiedShow Answer

Identify the product of the given reaction. ​

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The conjugated portion of the following molecule is circled.

Correct AnswerverifiedTrue

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The conjugated portion of the following molecule is circled.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedC

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

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

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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.

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C

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Identify the product of the given reaction.

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True

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

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C