Question 1

Explain why  SN1  reactions are favored by the use of a polar solvent.

Accepted Answer

The rate-limiting step in an

Question 2

Identify the HOMO and the LUMO in the reaction shown here.

Accepted Answer

The HOMO is a nonbon

Question 3

Draw a mechanism for the following transformation. Show all curved arrows, necessary lone pairs, and nonzero formal charges.

Accepted Answer

The answer of Draw a mechanism for the following transformation....

Question 4

Which of these alkyl bromides will react faster in an  SN2  reaction? Explain.

Accepted Answer

S_N2 reaction rates are sensitive to ster

Question 5

Draw the product of the following sequence of reactions. Show stereochemistry at any stereogenic carbon.

Accepted Answer

The answer of Draw the product of the following sequence...

Question 6

Draw the  SN2  product of the following reaction. Show stereochemistry at any stereogenic carbon.

Accepted Answer

The answer of Draw the  SN2  product of...

Question 7

In each pair shown, which  SN2  reaction would proceed faster?

Accepted Answer

a) Reaction 1; 
b) R

Question 8

Identify the product of the following reaction.

Accepted Answer

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

Question 9

Show how you would perform the following synthesis.Show the reagents you would use for each step and the organic intermediate formed in each step.

Accepted Answer

1) HBr
2)

Question 10

Which of the following expressions correctly states the rate law for the  SN2  reaction shown here?  (NaN3= sodium azide)

Accepted Answer

A)  rate  =k[2 -bromopropane  ] 
B)  rate  =k  [sodium azide] 
C)   rate  =k[2 -bromopropane ]  [sodium azide] 
D)   rate  =k[2 -bromopropane }2[  sodium azide ] 
E)  It is impossible to tell from the information given. 
A)  rate  =k[2 -bromopropane  ] 
B)  rate  =k  [sodium azide] 
C)   rate  =k[2 -bromopropane ]  [sodium azide] 
D)   rate  =k[2 -bromopropane }2[  sodium azide ] 
E)  It is impossible to tell from the information given.

Question 11

Use molecular orbital interactions to illustrate why  SN2  reactions proceed with inversion of configuration at the substrate.

Accepted Answer

11ec8288_e134_7ff7_8010_c7ee3ee7d603_TB3

Question 12

In which of the following instances would it be expected that the reaction would always have an equilibrium constant that is greater than 1 ?

Accepted Answer

A)   	ΔH  and  	ΔS  for the reaction are both positive. 
B)   	Δ H  for the reaction is positive, while  	Δ S  for the reaction is negative. 
C)  	ΔH  and 	ΔS  for the reaction are both negative. 
D)   	Δ H  and 	ΔS  for the reaction are both zero. 
E)   	ΔH  for the reaction is negative, while  	Δ S  for the reaction is positive. 
A)   	ΔH  and  	ΔS  for the reaction are both positive. 
B)   	Δ H  for the reaction is positive, while  	Δ S  for the reaction is negative. 
C)  	ΔH  and 	ΔS  for the reaction are both negative. 
D)   	Δ H  and 	ΔS  for the reaction are both zero. 
E)   	ΔH  for the reaction is negative, while  	Δ S  for the reaction is positive.

Question 13

Which of these is the most efficient method for making the ether shown in the highest possible yield using a Williamson ether synthesis?

Accepted Answer

A)    
B)    
C)    
D)    
E)  Methods b and d are equally efficient. 
A)    
B)    
C)    
D)    
E)  Methods b and d are equally efficient.

Question 14

Identify the HOMO  and the LUMO  in the following SN2  reaction.

Accepted Answer

A)  The HOMO is a bonding C-Br σ and the LUMO is an antibonding C-Br σ* . 
B)  The HOMO is a bonding C-Br σ*  and the LUMO is an antibonding  C-Br σ . 
C)  The HOMO is a nonbonding  (n)  on hydroxide ion and the LUMO is an antibonding  OH σ*. 
D)  The HOMO is a nonbonding  (n)  on hydroxide ion and the LUMO is an antibonding C-Br  σ* . 
E)  None of these choices correctly identify the HOMO and LUMO in this reaction. 
A)  The HOMO is a bonding C-Br σ and the LUMO is an antibonding C-Br σ* . 
B)  The HOMO is a bonding C-Br σ*  and the LUMO is an antibonding  C-Br σ . 
C)  The HOMO is a nonbonding  (n)  on hydroxide ion and the LUMO is an antibonding  OH σ*. 
D)  The HOMO is a nonbonding  (n)  on hydroxide ion and the LUMO is an antibonding C-Br  σ* . 
E)  None of these choices correctly identify the HOMO and LUMO in this reaction.

Question 15

Which of these molecules will react faster in an  SN1  reaction with methanol? Explain.

Accepted Answer

The rate-determining step in an S_N1 rea

Question 16

Draw the expected transition state geometry for each of these  SN2  reactions based on the reaction enthalpy values. (Hint: Will the TS look more like the reactant or the product?):

Accepted Answer

The answer of Draw the expected transition state geometry for...

Question 17

Which of the following is the product of this reaction?

Accepted Answer

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

Question 18

What is the likely product of reaction of dimethylamine with excess methyl iodide?

Accepted Answer

A)   HNI2 
B) HNMe3+I-  
C) NMe4+I- 
D)  HNMeI 
E)   Me3N 
A)   HNI2 
B) HNMe3+I-  
C) NMe4+I- 
D)  HNMeI 
E)   Me3N

Question 19

Outline a multistep synthesis of the target molecule from the starting material shown.You may
use any organic or inorganic reagents.Show the reagents necessary for each step and the product
of each step.

Accepted Answer

The answer of Outline a multistep synthesis of the target...

Question 20

Which of the following will react most slowly with cyanide nucleophile (NC-) in an  SN2  reaction?

Accepted Answer

A)   
B)   
C)   
D)   
E)  CH3I 
A)   
B)   
C)   
D)   
E)  CH3I

Exam 7: Substitution Reactions: the Sn2 and Sn1 Reactions

Explain why SN1 reactions are favored by the use of a polar solvent.

Identify the HOMO and the LUMO in the reaction shown here.

Draw a mechanism for the following transformation. Show all curved arrows, necessary lone pairs, and nonzero formal charges.

Which of these alkyl bromides will react faster in an SN2 reaction? Explain.

Draw the product of the following sequence of reactions. Show stereochemistry at any stereogenic carbon.

Draw the SN2 product of the following reaction. Show stereochemistry at any stereogenic carbon.

In each pair shown, which SN2 reaction would proceed faster?

Identify the product of the following reaction.

Show how you would perform the following synthesis.Show the reagents you would use for each step and the organic intermediate formed in each step.

Which of the following expressions correctly states the rate law for the SN2 reaction shown here? (NaN3= sodium azide)

Use molecular orbital interactions to illustrate why SN2 reactions proceed with inversion of configuration at the substrate.

In which of the following instances would it be expected that the reaction would always have an equilibrium constant that is greater than 1 ?

Which of these is the most efficient method for making the ether shown in the highest possible yield using a Williamson ether synthesis?

Identify the HOMO and the LUMO in the following SN2 reaction.

Which of these molecules will react faster in an SN1 reaction with methanol? Explain.

Draw the expected transition state geometry for each of these SN2 reactions based on the reaction enthalpy values. (Hint: Will the TS look more like the reactant or the product?):

Which of the following is the product of this reaction?

What is the likely product of reaction of dimethylamine with excess methyl iodide?

Outline a multistep synthesis of the target molecule from the starting material shown.You may use any organic or inorganic reagents.Show the reagents necessary for each step and the product of each step.

Which of the following will react most slowly with cyanide nucleophile (NC-) in an SN2 reaction?

Atoms and Molecules; Orbitals and Bonding

Alkanes

Alkenes and Alkynes

Stereochemistry

Rings

Substituted Alkanes: Alkyl Halides, Alcohols, Amines, Ethers,thiols, and Thioethers

Elimination Reactions: the E1 and E2 Reactions

Analytical Chemistry: Spectroscopy

Electrophilic Additions to Alkenes

More Additions to Bonds

Radical Reactions

Dienes and the Allyl System: 2p Orbitals in Conjugation

Aromaticity

Substitution Reactions of Aromatic Compounds

Carbonyl Chemistry 1: Addition Reactions

Carboxylic Acids

Derivatives of Carboxylic Acids: Acyl Compounds

Carbonyl Chemistry 2: Reactions at the Α Position

Special Topic: Carbohydrates

Special Topic: Bio-Organic Chemistry

Special Topic: Amino Acids and Polyamino Acids Peptides and Proteins

Special Topic: Reactions Controlled by Orbital Symmetry

Special Topic: Intramolecular Reactions and Neighboring Group Participation

Filters

Explain why S_N1 reactions are favored by the use of a polar solvent.

Which of these alkyl bromides will react faster in an S_N2 reaction? Explain.

In each pair shown, which S_N2 reaction would proceed faster?

Which of the following expressions correctly states the rate law for the S_N2 reaction shown here? (NaN₃= sodium azide)

Identify the HOMO and the LUMO in the following S_N2 reaction.

Which of the following will react most slowly with cyanide nucleophile (NC^-) in an S_N2 reaction?