Question 1

What is the major product obtained from the following reaction sequence?

Accepted Answer

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

Question 2

An alternate mechanism for the chlorination of methane is: Cl2 $\rightarrow$ 2Cl·
Cl-Cl,$\Delta$ H° = 243 kJ mol-1
Cl· + CH4 $\rightarrow$CH3Cl + H·
CH3-H,$\Delta$ H° = 440 kJ mol-1
H· + Cl2 $\rightarrow$ HCl + Cl·
CH3-Cl,$\Delta$ H° = 352 kJ mol-1
H-Cl,$\Delta$ H° = 432 kJ mol -1
This mechanism is unlikely because:

Accepted Answer

A)  The overall $\Delta$ H° is highly endothermic. 
B)  The probability factor is low. 
C)  One of the chain propagating steps is non-productive. 
D)  One of the chain propagating steps has a very high Eact. 
E)  One of the chain propagating steps is highly exothermic. 
A)  The overall $\Delta$ H° is highly endothermic. 
B)  The probability factor is low. 
C)  One of the chain propagating steps is non-productive. 
D)  One of the chain propagating steps has a very high Eact. 
E)  One of the chain propagating steps is highly exothermic. D

Question 3

What is the product for the following three-step reaction sequence?

Accepted Answer

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

Question 4

Free radical chlorination will produce but one monochloro derivative in the case of:

Accepted Answer

A)  Propane 
B)  Butane 
C)  Isobutane 
D)  Isopentane 
E)  Neopentane 
A)  Propane 
B)  Butane 
C)  Isobutane 
D)  Isopentane 
E)  Neopentane

Question 5

Which of the following reactions would have an activation energy equal to zero?

Accepted Answer

A)  H-H $\rightarrow$ 2H· 
B)  H· + CH3-H $\rightarrow$CH3--H + H· 
C)  CH3· + CH3· $\rightarrow$ CH3-CH3 
D)  CH3· + CH3-H $\rightarrow$ CH3-H + CH3· 
E)  All of the above 
A)  H-H $\rightarrow$ 2H· 
B)  H· + CH3-H $\rightarrow$CH3--H + H· 
C)  CH3· + CH3· $\rightarrow$ CH3-CH3 
D)  CH3· + CH3-H $\rightarrow$ CH3-H + CH3· 
E)  All of the above

Question 6

Draw bond-line formulas of all monochloro derivatives that might be formed when 1,1-dimethylcyclobutane is allowed to react with Cl2 under UV irradiation.For each structure,indicate,with an asterisk,any stereocenters that might be present.

Accepted Answer

Question 7

How many different monochlorobutanes (including stereoisomers)are formed in the free radical chlorination of butane?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 8

If propene polymerization is initiated by the use of diacyl peroxide,this is an intermediate species formed early in the process.

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 9

What is the product for the following three-step reaction sequence?

Accepted Answer

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

Question 10

An example of a reaction having an Eact = 0 would be:

Accepted Answer

A)  Br· + Br-Br --$\rightarrow$ Br-Br + Br· 
B)  F· + CH4 --$\rightarrow$ H-F + CH3· 
C)  CH3· + Cl· --$\rightarrow$ CH3Cl 
D)  More than one of these 
E)  None of these 
A)  Br· + Br-Br --$\rightarrow$ Br-Br + Br· 
B)  F· + CH4 --$\rightarrow$ H-F + CH3· 
C)  CH3· + Cl· --$\rightarrow$ CH3Cl 
D)  More than one of these 
E)  None of these

Question 11

The reaction of 1-butene with HBr in the presence of peroxides yields 1-bromobutane.The mechanism for the reaction involves:

Accepted Answer

A)  attack on the alkene by a Br+ ion. 
B)  attack on the alkene by a H+ ion. 
C)  attack on the alkene by a bromine atom,Br·. 
D)  attack on the alkene by a hydrogen atom,H·. 
E)  isomerization of the 2-bromobutane produced initially. 
A)  attack on the alkene by a Br+ ion. 
B)  attack on the alkene by a H+ ion. 
C)  attack on the alkene by a bromine atom,Br·. 
D)  attack on the alkene by a hydrogen atom,H·. 
E)  isomerization of the 2-bromobutane produced initially.

Question 12

What is the product for the following three-step reaction sequence?

Accepted Answer

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

Question 13

More than one monochloro compound can be obtained from the free radical chlorination of:

Accepted Answer

A)  Cyclopentane 
B)  Neopentane 
C)  Isobutane 
D)  Ethane 
E)  Methane 
A)  Cyclopentane 
B)  Neopentane 
C)  Isobutane 
D)  Ethane 
E)  Methane

Question 14

Consider the light-initiated chlorination of (S)-2-chlorobutane followed by careful fractional distillation (or separation by GLC)of all of the products with the formula C4H8Cl2.How many fractions (in total)would be obtained and how many of these fractions would be optically active?

Accepted Answer

A)  Three fractions total;all optically active 
B)  Four fractions total;three fractions optically active 
C)  Five fractions total;all optically active 
D)  Five fractions total;four fractions optically active 
E)  Five fractions total;three fractions optically active 
A)  Three fractions total;all optically active 
B)  Four fractions total;three fractions optically active 
C)  Five fractions total;all optically active 
D)  Five fractions total;four fractions optically active 
E)  Five fractions total;three fractions optically active

Question 15

For which of the following reactions would the transition state most resemble the products? The following bond dissociation energies may be useful. (CH3)2CH-H CH3CH2CH2-H H-F
(413 kJ mol-1) (423 kJ mol-1) (570 kJ mol-1)
H-Cl H-Br
(432 kJ mol-1) (366 kJ mol-1)

Accepted Answer

A) 
  
B)  CH3CH2CH3 + F· $\rightarrow$CH3CH2CH2· + HF 
C) 
  
D)  CH3CH2CH3 + Cl· $\rightarrow$ CH3CH2CH2· + HCl 
E)  CH3CH2CH3 + Br· $\rightarrow$CH3CH2CH2· + HBr 
A) 
  
B)  CH3CH2CH3 + F· $\rightarrow$CH3CH2CH2· + HF 
C) 
  
D)  CH3CH2CH3 + Cl· $\rightarrow$ CH3CH2CH2· + HCl 
E)  CH3CH2CH3 + Br· $\rightarrow$CH3CH2CH2· + HBr

Question 16

What is the major product obtained from the following reaction sequence?

Accepted Answer

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

Question 17

The bond dissociation energies for the relevant bonds are given below each of the species involved in the following reaction.Calculate the overall $\Delta$H° for the reaction.

Accepted Answer

A)  -121 kJ / mol 
B)  +121 kJ / mol 
C)  +243 kJ / mol 
D)  +664 kJ / mol 
E)  -785 kJ / mol 
A)  -121 kJ / mol 
B)  +121 kJ / mol 
C)  +243 kJ / mol 
D)  +664 kJ / mol 
E)  -785 kJ / mol

Question 18

The free radical chlorination of (R)-2-chloropentane forms a mixture of dichloropentanes which includes:

Accepted Answer

A)  three optically active compounds. 
B)  two achiral compounds. 
C)  two meso compounds. 
D)  one pair of diastereomers. 
E)  one racemic mixture. 
A)  three optically active compounds. 
B)  two achiral compounds. 
C)  two meso compounds. 
D)  one pair of diastereomers. 
E)  one racemic mixture.

Question 19

Draw bond-line formulas of all dichloro derivatives that might be formed when 1-chloro-2,2,3,3,-tetramethylpentane is allowed to react with Cl2 under UV irradiation.For each structure,indicate,with an asterisk,any stereocenters that might be present.

Accepted Answer

Question 20

What product would result from the following reaction?

Accepted Answer

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

Exam 10: Radical Reactions

What is the major product obtained from the following reaction sequence?

What is the product for the following three-step reaction sequence?

Free radical chlorination will produce but one monochloro derivative in the case of:

Which of the following reactions would have an activation energy equal to zero?

Draw bond-line formulas of all monochloro derivatives that might be formed when 1,1-dimethylcyclobutane is allowed to react with Cl2 under UV irradiation.For each structure,indicate,with an asterisk,any stereocenters that might be present.

How many different monochlorobutanes (including stereoisomers)are formed in the free radical chlorination of butane?

If propene polymerization is initiated by the use of diacyl peroxide,this is an intermediate species formed early in the process.

What is the product for the following three-step reaction sequence?

An example of a reaction having an Eact = 0 would be:

The reaction of 1-butene with HBr in the presence of peroxides yields 1-bromobutane.The mechanism for the reaction involves:

What is the product for the following three-step reaction sequence?

More than one monochloro compound can be obtained from the free radical chlorination of:

Consider the light-initiated chlorination of (S)-2-chlorobutane followed by careful fractional distillation (or separation by GLC)of all of the products with the formula C4H8Cl2.How many fractions (in total)would be obtained and how many of these fractions would be optically active?

For which of the following reactions would the transition state most resemble the products? The following bond dissociation energies may be useful. (CH3)2CH-H CH3CH2CH2-H H-F (413 kJ mol-1) (423 kJ mol-1) (570 kJ mol-1) H-Cl H-Br (432 kJ mol-1) (366 kJ mol-1)

What is the major product obtained from the following reaction sequence?

The bond dissociation energies for the relevant bonds are given below each of the species involved in the following reaction.Calculate the overall Δ\DeltaΔ H° for the reaction.

The free radical chlorination of (R)-2-chloropentane forms a mixture of dichloropentanes which includes:

Draw bond-line formulas of all dichloro derivatives that might be formed when 1-chloro-2,2,3,3,-tetramethylpentane is allowed to react with Cl2 under UV irradiation.For each structure,indicate,with an asterisk,any stereocenters that might be present.

What product would result from the following reaction?

Carbon Compounds and Chemical Bonds

Representative Carbon Compounds: Functional Groups, Intermolecular Forces, and Infrared Ir Spectroscopy

An Introduction to Organic Reactions: Acids and Bases

Alkanes: Nomenclature, Conformational Analysis, and an Introduction to Synthesis

Stereochemistry: Chiral Molecules

Ionic Reactions - Nucleophilic Substitution and Elimination Reactions of Alkyl Halides

Alkenes and Alkynes I: Properties and Synthesis, Elimination Reactions of Alkyl Halides

Alkenes and Alkynes Ii: Addition Reactions

Nuclear Magnetic Resonance and Mass Spectrometry: Tools for Structure Determination

Alcohols and Ethers

Alcohols From Carbonyl Compounds Oxidation-Reduction and Organometallic Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones I Nucleophilic Addition to the Carbonyl Group

Aldehydes and Ketones Ii Aldol Reactions

Carboxylic Acids and Their Derivatives Nucleophilic Addition - Elimination at the Acyl Carbon

Synthesis and Reactions of Beta-Dicarbonyl Compounds: More Chemistry of Enolate Ions

Amines

Phenols and Aryl Halides: Nucleophilic Aromatic Substitution

Carbohydrates

Lipids

Amino Acids and Proteins

Nucleic Acids and Protein Synthesis

Filters

Draw bond-line formulas of all monochloro derivatives that might be formed when 1,1-dimethylcyclobutane is allowed to react with Cl₂ under UV irradiation.For each structure,indicate,with an asterisk,any stereocenters that might be present.

An example of a reaction having an E_act = 0 would be:

Consider the light-initiated chlorination of (S)-2-chlorobutane followed by careful fractional distillation (or separation by GLC)of all of the products with the formula C₄H₈Cl₂.How many fractions (in total)would be obtained and how many of these fractions would be optically active?

For which of the following reactions would the transition state most resemble the products? The following bond dissociation energies may be useful. (CH₃)₂CH-H CH₃CH₂CH₂-H H-F (413 kJ mol^-1) (423 kJ mol^-1) (570 kJ mol^-1) H-Cl H-Br (432 kJ mol^-1) (366 kJ mol^-1)

Draw bond-line formulas of all dichloro derivatives that might be formed when 1-chloro-2,2,3,3,-tetramethylpentane is allowed to react with Cl₂ under UV irradiation.For each structure,indicate,with an asterisk,any stereocenters that might be present.