Question 1

Which of the labeled hydrogens is most easily abstracted in a free radical bromination reaction?

Accepted Answer

A) Ha 
B) Hb 
C) Hc 
D) Hd 
A) Ha 
B) Hb 
C) Hc 
D) Hd B

Question 2

Select the route that would most likely produce the desired results from the given starting material.   I.(1)H2SO4 and heat; (2)HBr II.(1)KOH in ethanol; (2)HBr
III)(1)H2SO4 and heat; (2)HBr + peroxides
IV)(1)potassium tert-butoxide in tert-butanol; (2)HBr + peroxides

Accepted Answer

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

Question 3

Which steps are the rate-determining step in the mechanism of radical halogenation?

Accepted Answer

A) Initiation 
B) Propagation 
C) Termination 
D) Initiation and propagation 
A) Initiation 
B) Propagation 
C) Termination 
D) Initiation and propagation B

Question 4

How many monochlorination products (constitutional isomers and stereoisomers)are formed from the reaction of pentane with Cl2 and hn?

Accepted Answer

A) 2 
B) 3 
C) 4 
D) 5 
A) 2 
B) 3 
C) 4 
D) 5

Question 5

How many monochlorination products can be formed (constitutional isomers only)from the reaction of CH3CH2CH2CH2CH2CH3 with Cl2 and hn?

Accepted Answer

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

Question 6

Which of the following would be the fastest to form a radical?

Accepted Answer

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

Question 7

A possible reaction of ethane with chlorine is shown below.   This reaction could conceivably occur by the following chain mechanisms [1],[2],and [3].Determine DH for step [2].   Bond dissociation energies (kcal/mol):

Accepted Answer

A) -5 kcal/mol 
B) +58 kcal/mol 
C) -28 kcal/mol 
D) None of the choices are correct. 
A) -5 kcal/mol 
B) +58 kcal/mol 
C) -28 kcal/mol 
D) None of the choices are correct.

Question 8

A possible reaction of ethane with chlorine is shown below.   This reaction could conceivably occur by the following chain mechanisms [1],[2],and [3].The chain propagating step(s)is (are)________.

Accepted Answer

A) Only [1] and [2] 
B) Only [2] and [3] 
C) Only [1] and [3] 
D) Only [3] 
A) Only [1] and [2] 
B) Only [2] and [3] 
C) Only [1] and [3] 
D) Only [3]

Question 9

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

Accepted Answer

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

Question 10

Which of the following compounds contain primary (1°)radical carbons?

Accepted Answer

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

Question 11

Which of the following compounds contain secondary (2°)radical carbons?

Accepted Answer

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

Question 12

Which of the following statements about the stereochemistry of halogenation reactions is true?

Accepted Answer

A) An achiral starting material always gives an achiral product only. 
B) An achiral starting material always gives a racemic product only. 
C) The configuration at a stereogenic center of a product must change even if a reaction does not occur at a stereogenic center. 
D) An achiral starting material always gives either an achiral or a racemic product. 
A) An achiral starting material always gives an achiral product only. 
B) An achiral starting material always gives a racemic product only. 
C) The configuration at a stereogenic center of a product must change even if a reaction does not occur at a stereogenic center. 
D) An achiral starting material always gives either an achiral or a racemic product.

Question 13

Which of the following statements about radicals is true?

Accepted Answer

A) Cleavage of a stronger bond forms the more stable radical. 
B) The stability of a radical increases as the number of alkyl groups bonded to the radical carbon decreases. 
C) The higher the bond dissociation energy for a C-H bond,the more stable the resulting carbon radical. 
D) Less stable radicals generally do not rearrange to more stable radicals. 
A) Cleavage of a stronger bond forms the more stable radical. 
B) The stability of a radical increases as the number of alkyl groups bonded to the radical carbon decreases. 
C) The higher the bond dissociation energy for a C-H bond,the more stable the resulting carbon radical. 
D) Less stable radicals generally do not rearrange to more stable radicals.

Question 14

How many monochlorination products,including stereoisomers,are formed from (S,S)-1,2-dimethylcyclopropane?

Accepted Answer

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

Question 15

What is the product in the following sequence of reactions?

Accepted Answer

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

Question 16

Which of the following compounds contain tertiary (3°)radical carbons?

Accepted Answer

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

Question 17

What is the product of the following reaction?

Accepted Answer

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

Question 18

How many monochlorination products (constitutional isomers and stereoisomers)are formed from the reaction of butane with Cl2 and hn?

Accepted Answer

A) 2 
B) 3 
C) 4 
D) 5 
A) 2 
B) 3 
C) 4 
D) 5

Question 19

Determine the monochlorination product(s).

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 20

What is the product of the following reaction?

Accepted Answer

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

Exam 13: Radical Reactions

Which of the labeled hydrogens is most easily abstracted in a free radical bromination reaction?

Select the route that would most likely produce the desired results from the given starting material. I.(1)H2SO4 and heat; (2)HBr II.(1)KOH in ethanol; (2)HBr III)(1)H2SO4 and heat; (2)HBr + peroxides IV)(1)potassium tert-butoxide in tert-butanol; (2)HBr + peroxides

Which steps are the rate-determining step in the mechanism of radical halogenation?

How many monochlorination products (constitutional isomers and stereoisomers)are formed from the reaction of pentane with Cl2 and hn?

How many monochlorination products can be formed (constitutional isomers only)from the reaction of CH3CH2CH2CH2CH2CH3 with Cl2 and hn?

Which of the following would be the fastest to form a radical?

A possible reaction of ethane with chlorine is shown below. This reaction could conceivably occur by the following chain mechanisms [1],[2],and [3].Determine DH for step [2]. Bond dissociation energies (kcal/mol):

A possible reaction of ethane with chlorine is shown below. This reaction could conceivably occur by the following chain mechanisms [1],[2],and [3].The chain propagating step(s)is (are)________.

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

Which of the following compounds contain primary (1°)radical carbons?

Which of the following compounds contain secondary (2°)radical carbons?

Which of the following statements about the stereochemistry of halogenation reactions is true?

Which of the following statements about radicals is true?

How many monochlorination products,including stereoisomers,are formed from (S,S)-1,2-dimethylcyclopropane?

What is the product in the following sequence of reactions?

Which of the following compounds contain tertiary (3°)radical carbons?

What is the product of the following reaction?

How many monochlorination products (constitutional isomers and stereoisomers)are formed from the reaction of butane with Cl2 and hn?

Determine the monochlorination product(s).

What is the product of the following reaction?

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

Alkenes and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Conjugation,resonance,and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Spectroscopy A: Mass Spectrometry

Spectroscopy B: Infrared Spectroscopy

Spectroscopy C: Nuclear Magnetic Resonance Spectroscopy

Filters

Select the route that would most likely produce the desired results from the given starting material. I.(1)H₂SO₄ and heat; (2)HBr II.(1)KOH in ethanol; (2)HBr III)(1)H₂SO₄ and heat; (2)HBr + peroxides IV)(1)potassium tert-butoxide in tert-butanol; (2)HBr + peroxides

How many monochlorination products (constitutional isomers and stereoisomers)are formed from the reaction of pentane with Cl₂ and hn?

How many monochlorination products can be formed (constitutional isomers only)from the reaction of CH₃CH₂CH₂CH₂CH₂CH₃ with Cl₂ and hn?

How many monochlorination products (constitutional isomers and stereoisomers)are formed from the reaction of butane with Cl₂ and hn?