Question 1

Which of the following compound absorbs UV light at the longest wavelength?

Accepted Answer

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

Question 2

Rank the following compounds in order of increasing stability, putting the least stable first.

Accepted Answer

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

Question 3

What is the reactive intermediate in the reaction of 1,3-diene with HBr, resulting in 1,4-addition?

Accepted Answer

A) Allylic radical 
B) Cyclic bromonium 
C) Dienophile 
D) Allylic carbocation 
A) Allylic radical 
B) Cyclic bromonium 
C) Dienophile 
D) Allylic carbocation

Question 4

Which triene absorbs the longest wavelength of UV light?

Accepted Answer

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

Question 5

Which of the following statements about kinetic vs.thermodynamic products is true?

Accepted Answer

A) The product that is formed faster is the thermodynamic product. 
B) The kinetic product predominates at low temperature. 
C) The product that predominates at equilibrium is the kinetic product. 
D) The thermodynamic product is less stable. 
A) The product that is formed faster is the thermodynamic product. 
B) The kinetic product predominates at low temperature. 
C) The product that predominates at equilibrium is the kinetic product. 
D) The thermodynamic product is less stable.

Question 6

Which of the following statements about the mechanism of the Diels-Alder reaction is true?

Accepted Answer

A) Three π bonds break; two σ bonds and one π bond form. 
B) Three π bonds break; one σ bond and two π bonds form. 
C) Two π bonds break; one σ bond and one π bond form. 
D) Two π bonds break; two σ bonds and one π bond form. 
A) Three π bonds break; two σ bonds and one π bond form. 
B) Three π bonds break; one σ bond and two π bonds form. 
C) Two π bonds break; one σ bond and one π bond form. 
D) Two π bonds break; two σ bonds and one π bond form.

Question 7

What is the major organic product of the following reaction?

Accepted Answer

A) Only I 
B) Only I and II 
C) Only II and III 
D) I, II, and III 
A) Only I 
B) Only I and II 
C) Only II and III 
D) I, II, and III

Question 8

What is (are) the major product(s) of the following reaction?

Accepted Answer

A) Only I 
B) Only II 
C) Only I and II 
D) I, II, and III 
A) Only I 
B) Only II 
C) Only I and II 
D) I, II, and III

Question 9

Which of the following is not a resonance structure of acetic anhydride?

Accepted Answer

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

Question 10

Which of the following is the least reactive diene in a Diels-Alder reaction?

Accepted Answer

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

Question 11

What is the hybridization around the indicated carbon atom in the following anion?

Accepted Answer

A) sp3 
B) sp2 
C) sp 
D) p 
A) sp3 
B) sp2 
C) sp 
D) p

Question 12

Which of the following is the most reactive diene in a Diels-Alder reaction?

Accepted Answer

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

Question 13

Rank the following dienophile in order of increasing reactivity in a Diels-Alder reaction, listing the least reactive first.

Accepted Answer

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

Question 14

What is the major organic product of the following reaction?

Accepted Answer

A) Only I 
B) Only II 
C) Only III 
D) Only I and II 
A) Only I 
B) Only II 
C) Only III 
D) Only I and II

Question 15

Which of the following statements about resonance structures is true?

Accepted Answer

A) The placement of atoms is different. 
B) The placement of p bonds is different. 
C) The placement of s bonds is different. 
D) The placement of nonbonded electrons is the same. 
A) The placement of atoms is different. 
B) The placement of p bonds is different. 
C) The placement of s bonds is different. 
D) The placement of nonbonded electrons is the same.

Question 16

Which of the following compounds is the most reactive dienophile in a Diels-Alder reaction?

Accepted Answer

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

Question 17

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

Accepted Answer

A) 3-Bromo-1-butene 
B) 1-Bromo-2-butene 
C) 2-Bromo-2-butene 
D) 2-Bromo-1-butene 
A) 3-Bromo-1-butene 
B) 1-Bromo-2-butene 
C) 2-Bromo-2-butene 
D) 2-Bromo-1-butene

Question 18

Which of the following electronic transitions is common in the UV spectrum of 1,3-butadiene?

Accepted Answer

A) sp 
B) sp* 
C) n p* 
D) pp* 
A) sp 
B) sp* 
C) n p* 
D) pp*

Question 19

Which of the following compound absorbs UV light at the longest wavelength?

Accepted Answer

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

Question 20

Which of the following is not a product obtained from the addition of 1 equivalent of HBr to (E)-1,3-pentadiene?

Accepted Answer

A) (
E) -4-Bromo-2-pentene 
B) (
E) -1-Bromo-2-pentene 
C) 3-Bromo-1-pentene 
D) (
E) -3-Bromo-2-pentene 
A) (
E) -4-Bromo-2-pentene 
B) (
E) -1-Bromo-2-pentene 
C) 3-Bromo-1-pentene 
D) (
E) -3-Bromo-2-pentene

Exam 16: Conjugation, Resonance, and Dienes

Which of the following compound absorbs UV light at the longest wavelength?

Rank the following compounds in order of increasing stability, putting the least stable first.

What is the reactive intermediate in the reaction of 1,3-diene with HBr, resulting in 1,4-addition?

Which triene absorbs the longest wavelength of UV light?

Which of the following statements about kinetic vs.thermodynamic products is true?

Which of the following statements about the mechanism of the Diels-Alder reaction is true?

What is the major organic product of the following reaction?

What is (are) the major product(s) of the following reaction?

Which of the following is not a resonance structure of acetic anhydride?

Which of the following is the least reactive diene in a Diels-Alder reaction?

What is the hybridization around the indicated carbon atom in the following anion?

Which of the following is the most reactive diene in a Diels-Alder reaction?

Rank the following dienophile in order of increasing reactivity in a Diels-Alder reaction, listing the least reactive first.

What is the major organic product of the following reaction?

Which of the following statements about resonance structures is true?

Which of the following compounds is the most reactive dienophile in a Diels-Alder reaction?

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

Which of the following electronic transitions is common in the UV spectrum of 1,3-butadiene?

Which of the following compound absorbs UV light at the longest wavelength?

Which of the following is not a product obtained from the addition of 1 equivalent of HBr to (E)-1,3-pentadiene?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols, Ethers, and Related Compounds

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Mass Spectrometry and Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

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Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Carboxylic Acids and the Acidity of the O-H Bond

Introduction to Carbonyl Chemistry;

Aldehydes and Ketones Nucleophilic Addition

Carboxylic Acids and Derivatives

Substitution Reactions of Carbonyl Compounds at the Alpha-Carbon

Carbonyl Condensation Reactions

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Carbon-Carbon Bond Forming Reactions in Organic Synthesis

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