Question 1

Which of the following terms describes the mechanism for the addition of Br2 to butadiene?

Accepted Answer

A)  electrophilic addition 
B)  nucleophilic addition 
C)  pericyclic addition 
D)  conjugate addition 
A)  electrophilic addition 
B)  nucleophilic addition 
C)  pericyclic addition 
D)  conjugate addition A

Question 2

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

Accepted Answer

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

Question 3

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

Accepted Answer

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

Question 4

Which of the following arrangements of p atomic orbitals gives the lowest energy p-bonding 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 5

What is the reactive intermediate in the reaction of 1,3-butadiene with HBr resulting in 1,2-addition?

Accepted Answer

A)  cyclic bromonium cation 
B)  allylic cation 
C)  allylic radical 
D)  dienophile 
A)  cyclic bromonium cation 
B)  allylic cation 
C)  allylic radical 
D)  dienophile

Question 6

Which of the following arrangements of p atomic orbitals gives the highest energy p-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 7

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

Accepted Answer

A)  J*mol-1 
B)  M-1 
C)  nm 
D)  none, lmax is a dimensionless quantity 
A)  J*mol-1 
B)  M-1 
C)  nm 
D)  none, lmax is a dimensionless quantity

Question 8

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 9

Which of the following energy diagrams represents the electronic state of butadiene after absorption of radiation?

Accepted Answer

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

Question 10

Draw two resonance structures of the reactive intermediate that accounts for the formation of 1,2- and 1,4-addition products upon reaction of 1,3-butadiene with one equivalent of bromine.

Accepted Answer

The answer of Draw two resonance structures of the reactive...

Question 11

What is the thermodynamic product obtained from the addition of 1 mole of bromine to 1,3-butadiene?

Accepted Answer

A)  3,4-dibromo-1-butene 
B)  (
E) -1,4-dibromo-2-butene 
C)  (Z)-1,4-dibromo-2-butene 
D)  (Z)-2,3-dibromo-2-butene 
A)  3,4-dibromo-1-butene 
B)  (
E) -1,4-dibromo-2-butene 
C)  (Z)-1,4-dibromo-2-butene 
D)  (Z)-2,3-dibromo-2-butene

Question 12

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 13

What is the kinetic product obtained from the addition of 1 mole of bromine to 1,3-butadiene?

Accepted Answer

A)  3,4-dibromo-1-butene 
B)  (
E) -1,4-dibromo-2-butene 
C)  (Z)-1,4-dibromo-2-butene 
D)  (Z)-2,3-dibromo-2-butene 
A)  3,4-dibromo-1-butene 
B)  (
E) -1,4-dibromo-2-butene 
C)  (Z)-1,4-dibromo-2-butene 
D)  (Z)-2,3-dibromo-2-butene

Question 14

Which of the following processes takes place upon absorption of ultraviolet-visible radiation?

Accepted Answer

A)  bond vibration 
B)  electron excitation 
C)  nuclear spin flip 
D)  electron spin flip 
A)  bond vibration 
B)  electron excitation 
C)  nuclear spin flip 
D)  electron spin flip

Question 15

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 16

Which of the following is(are) formed upon addition of 1 mol of Br2 to 1,3-cyclohexane?

Accepted Answer

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

Question 17

What is the systematic IUPAC name of the following compound?

Accepted Answer

A)  (3S,4
E) -3-ethyl-3,4-dimethyl-1,4-hexadiene 
B)  (3R,4
E) -3-ethyl-3,4-dimethyl-1,4-hexadiene 
C)  (3S,4Z)-3-ethyl-3,4-dimethyl-1,4-hexadiene 
D)  (3R,4Z)-3-ethyl-3,4-dimethyl-1,4-hexadiene 
A)  (3S,4
E) -3-ethyl-3,4-dimethyl-1,4-hexadiene 
B)  (3R,4
E) -3-ethyl-3,4-dimethyl-1,4-hexadiene 
C)  (3S,4Z)-3-ethyl-3,4-dimethyl-1,4-hexadiene 
D)  (3R,4Z)-3-ethyl-3,4-dimethyl-1,4-hexadiene

Question 18

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

Question 19

Provide the structures of the constitutional isomers of the two major organic products obtained from the following reaction?

Accepted Answer

The answer of Provide the structures of the constitutional isomers...

Question 20

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

Accepted Answer

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

Exam 20: Dienes, Conjugated Systems, and Pericyclic Reactions

Which of the following terms describes the mechanism for the addition of Br2 to butadiene?

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

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

Which of the following arrangements of p atomic orbitals gives the lowest energy p-bonding molecular orbital of 1,3-butadiene?

What is the reactive intermediate in the reaction of 1,3-butadiene with HBr resulting in 1,2-addition?

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

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

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

Which of the following energy diagrams represents the electronic state of butadiene after absorption of radiation?

Draw two resonance structures of the reactive intermediate that accounts for the formation of 1,2- and 1,4-addition products upon reaction of 1,3-butadiene with one equivalent of bromine.

What is the thermodynamic product obtained from the addition of 1 mole of bromine to 1,3-butadiene?

What is the IUPAC name of the following compound?

What is the kinetic product obtained from the addition of 1 mole of bromine to 1,3-butadiene?

Which of the following processes takes place upon absorption of ultraviolet-visible radiation?

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

Which of the following is(are) formed upon addition of 1 mol of Br2 to 1,3-cyclohexane?

What is the systematic IUPAC name of the following compound?

Which of the following are conjugated dienes?

Provide the structures of the constitutional isomers of the two major organic products obtained from the following reaction?

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

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

Filters

Which of the following terms describes the mechanism for the addition of Br₂ to butadiene?

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

Which of the following is(are) formed upon addition of 1 mol of Br₂ to 1,3-cyclohexane?

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