Question 1

Racemic mixtures form in SN1 reactions when leaving group departure results in a loss of chirality followed by subsequent attack of the nucleophile.

Accepted Answer

A) True 
 B)False

Question 2

The rate equation for a nucleophilic substitution reaction of a secondary alkyl chloride (R-Cl)with I- ion would be:

Accepted Answer

A) Rate = k [RCl] 
B) Rate = k [I-] 
C) Rate = k [RCl][I-] 
D) Rate = k [RCl]2[I-] 
E) Rate = k [RCl][I-]2 
A) Rate = k [RCl] 
B) Rate = k [I-] 
C) Rate = k [RCl][I-] 
D) Rate = k [RCl]2[I-] 
E) Rate = k [RCl][I-]2

Question 3

What final product is likely to be obtained through the following series of reactions?

Accepted Answer

The answer of What final product is likely to be...

Question 4

What product(s)would you expect to obtain from the following SN2 reaction?

Accepted Answer

A) I 
B) II 
C) An equimolar mixture of I and II. 
D) III 
E) None of these choices. 
A) I 
B) II 
C) An equimolar mixture of I and II. 
D) III 
E) None of these choices.

Question 5

Which nucleophilic substitution reaction would be unlikely to occur?

Accepted Answer

A) HO- + CH3CH2-I $\to$ CH3CH2-OH + I- 
B) I- + CH3CH2-H $\to$ CH3CH2-I + H- 
C) CH3S- + CH3-Br $\to$ CH3S-CH3 + Br- 
D) All of these choices would be unlikely to occur. 
E) None of these choices would be unlikely to occur. 
A) HO- + CH3CH2-I $\to$ CH3CH2-OH + I- 
B) I- + CH3CH2-H $\to$ CH3CH2-I + H- 
C) CH3S- + CH3-Br $\to$ CH3S-CH3 + Br- 
D) All of these choices would be unlikely to occur. 
E) None of these choices would be unlikely to occur.

Question 6

SN2 reactions of the type,Nu- + RL $\to$Nu-R + L-, are favored

Accepted Answer

A) when tertiary substrates are used. 
B) by using a high concentration of the nucleophile. 
C) by using a solvent of high polarity. 
D) by the use of weak nucleophiles. 
E) by none of these choices. 
A) when tertiary substrates are used. 
B) by using a high concentration of the nucleophile. 
C) by using a solvent of high polarity. 
D) by the use of weak nucleophiles. 
E) by none of these choices.

Question 7

Select the potential energy diagram that represents a single-step endothermic (endergonic)reaction.

Accepted Answer

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

Question 8

Which is a polar aprotic solvent?

Accepted Answer

A) 2-methylhexane 
B) CCl4 
C) NH3(l) 
D) CH3CH2CH2OCH2CH2CH3 
E) 2-methyl-2-propanol 
A) 2-methylhexane 
B) CCl4 
C) NH3(l) 
D) CH3CH2CH2OCH2CH2CH3 
E) 2-methyl-2-propanol

Question 9

Which nucleophilic substitution reaction would be likely to occur (although probably not in excellent yield,due to competing elimination)?

Accepted Answer

A) HO- + CH3CH2CH2CHICH3 $\to$CH3 CH2CH2CHOHCH3 + I- 
B) Cl-+ CH3CH2CH2CH2-OH $\to$CH3CH2CH2CH2-Cl + OH- 
C) CH3S- + CH3CH2CH2-OCH3 $\to$CH3S-CH2CH2CH3 + OCH3--- 
D) All of these choices are likely to occur. 
E) None of these choices are likely to occur. 
A) HO- + CH3CH2CH2CHICH3 $\to$CH3 CH2CH2CHOHCH3 + I- 
B) Cl-+ CH3CH2CH2CH2-OH $\to$CH3CH2CH2CH2-Cl + OH- 
C) CH3S- + CH3CH2CH2-OCH3 $\to$CH3S-CH2CH2CH3 + OCH3--- 
D) All of these choices are likely to occur. 
E) None of these choices are likely to occur.

Question 10

If the rate of reaction of [0.1 M] sodium cyanide with [0.1 M] 2-bromo-2-methylpropane is 1.2 x 10-3 M/s,what would be the effect on the overall rate if the concentration of sodium cyanide is increased to [0.2 M] and the concentration of the alkyl bromide is decreased to [0.05 M]?

Accepted Answer

A) the rate will increase by a factor of 2 
B) the rate will decrease by a factor of 2 
C) the rate will increase by a factor of 10 
D) the rate will decrease by a factor of 10 
E) the rate will remain unchanged 
A) the rate will increase by a factor of 2 
B) the rate will decrease by a factor of 2 
C) the rate will increase by a factor of 10 
D) the rate will decrease by a factor of 10 
E) the rate will remain unchanged

Question 11

In order for colliding species to react,they must ___ and ___.

Accepted Answer

have energy equal/gr

Question 12

Which of the following solvents will best promote a nucleophilic reaction between NaCN and 1-bromopropane?

Accepted Answer

A) H2O/MeOH mixture 
B) H2O 
C) MeCN 
D) HF(aq) 
E) running with no solvent 
A) H2O/MeOH mixture 
B) H2O 
C) MeCN 
D) HF(aq) 
E) running with no solvent

Question 13

What final product is likely to be obtained through the following series of reactions?

Accepted Answer

The answer of What final product is likely to be...

Question 14

Which of the following statements is (are)true of SN1 reactions of alkyl halides in general?

Accepted Answer

A) The rate of an SN1 reaction depends on the concentration of the alkyl halide. 
B) The rate of an SN1 reaction depends on the concentration of the nucleophile. 
C) SN1 reactions of alkyl halides occur faster in polar aprotic solvents (compared to protic solvents). 
D) The rate of an SN1 reaction depends on the concentration of the alkyl halide and SN1 reactions of alkyl halides occur faster in polar aprotic solvents (compared to protic solvents). 
E) The rate of an SN1 reaction depends on the concentration of the alkyl halide and the concentration of the nucleophile,and SN1 reactions of alkyl halides occur faster in polar aprotic solvents (compared to protic solvents). 
A) The rate of an SN1 reaction depends on the concentration of the alkyl halide. 
B) The rate of an SN1 reaction depends on the concentration of the nucleophile. 
C) SN1 reactions of alkyl halides occur faster in polar aprotic solvents (compared to protic solvents). 
D) The rate of an SN1 reaction depends on the concentration of the alkyl halide and SN1 reactions of alkyl halides occur faster in polar aprotic solvents (compared to protic solvents). 
E) The rate of an SN1 reaction depends on the concentration of the alkyl halide and the concentration of the nucleophile,and SN1 reactions of alkyl halides occur faster in polar aprotic solvents (compared to protic solvents).

Question 15

Which is not a polar aprotic solvent?

Accepted Answer

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

Question 16

The hybridization state of the charged carbon in a carbocation is ___.

Accepted Answer

A) sp4 
B) sp3 
C) sp2 
D) sp 
E) s 
A) sp4 
B) sp3 
C) sp2 
D) sp 
E) s

Question 17

The major product of the following reaction would be:

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) An equimolar mixture of I and II. 
A) I 
B) II 
C) III 
D) IV 
E) An equimolar mixture of I and II.

Question 18

Which is the strongest nucleophile?

Accepted Answer

A) OH- 
B) CH3CH2O- 
C)    
D) CH3CH2OH 
E) H2O 
A) OH- 
B) CH3CH2O- 
C)    
D) CH3CH2OH 
E) H2O

Question 19

The stabilizing effect of alkyl substituents on carbocations can be explained through ___.

Accepted Answer

The answer of The stabilizing effect of alkyl substituents on...

Question 20

Which SN2 reaction would you expect to take place most rapidly? Assume that the concentrations of the reactants and the temperature are the same in each instance.

Accepted Answer

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

Exam 6: Nucleophilic Reactions

Racemic mixtures form in SN1 reactions when leaving group departure results in a loss of chirality followed by subsequent attack of the nucleophile.

The rate equation for a nucleophilic substitution reaction of a secondary alkyl chloride (R-Cl)with I- ion would be:

What final product is likely to be obtained through the following series of reactions?

What product(s)would you expect to obtain from the following SN2 reaction?

Which nucleophilic substitution reaction would be unlikely to occur?

SN2 reactions of the type,Nu- + RL →\to→ Nu-R + L-, are favored

Select the potential energy diagram that represents a single-step endothermic (endergonic)reaction.

Which is a polar aprotic solvent?

Which nucleophilic substitution reaction would be likely to occur (although probably not in excellent yield,due to competing elimination)?

If the rate of reaction of [0.1 M] sodium cyanide with [0.1 M] 2-bromo-2-methylpropane is 1.2 x 10-3 M/s,what would be the effect on the overall rate if the concentration of sodium cyanide is increased to [0.2 M] and the concentration of the alkyl bromide is decreased to [0.05 M]?

In order for colliding species to react,they must ___ and ___.

Which of the following solvents will best promote a nucleophilic reaction between NaCN and 1-bromopropane?

What final product is likely to be obtained through the following series of reactions?

Which of the following statements is (are)true of SN1 reactions of alkyl halides in general?

Which is not a polar aprotic solvent?

The hybridization state of the charged carbon in a carbocation is ___.

The major product of the following reaction would be:

Which is the strongest nucleophile?

The stabilizing effect of alkyl substituents on carbocations can be explained through ___.

Which SN2 reaction would you expect to take place most rapidly? Assume that the concentrations of the reactants and the temperature are the same in each instance.

The Basics

Families of Carbon

Acids and Bases

Nomenclature and Conformations of Alkanes and Cycloalkanes

Stereochemistry

Alkenes and Alkynes I

Alkenes and Alkynes II

Nuclear Magnetic Resonance and Mass Spectrometry

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Reactions at the Α Carbon of Carbonyl Compounds

Condensation and Conjugate Addition Reactions of Carbonyl Compounds

Amines

Transition Metal Complexes

Carbohydrates

Lipids

Amino Acids and Proteins

Nucleic Acids and Protein Synthesis

Filters

Racemic mixtures form in S_N1 reactions when leaving group departure results in a loss of chirality followed by subsequent attack of the nucleophile.

The rate equation for a nucleophilic substitution reaction of a secondary alkyl chloride (R-Cl)with I^- ion would be:

What product(s)would you expect to obtain from the following S_N2 reaction?

S_N2 reactions of the type,Nu^- + RL $\to$ Nu-R + L^-,are favored

If the rate of reaction of [0.1 M] sodium cyanide with [0.1 M] 2-bromo-2-methylpropane is 1.2 x 10^-3 M/s,what would be the effect on the overall rate if the concentration of sodium cyanide is increased to [0.2 M] and the concentration of the alkyl bromide is decreased to [0.05 M]?

In order for colliding species to react,they must _ and _.

Which of the following statements is (are)true of S_N1 reactions of alkyl halides in general?

Which S_N2 reaction would you expect to take place most rapidly? Assume that the concentrations of the reactants and the temperature are the same in each instance.