Question 1

Which of the following is a feasible substitution reaction?

Accepted Answer

A) CH3CH2Cl + NaBr $\to$  CH3CH2Br + NaCl 
B) CH3CH3 + NaCN $\to$  CH3CH2CN + NaH 
C) CH3CH2Cl + NaOH $\to$ CH2=CH2 + H2O + NaCl 
D) More than one of these choices. 
E) None of these choices. 
A) CH3CH2Cl + NaBr $\to$  CH3CH2Br + NaCl 
B) CH3CH3 + NaCN $\to$  CH3CH2CN + NaH 
C) CH3CH2Cl + NaOH $\to$ CH2=CH2 + H2O + NaCl 
D) More than one of these choices. 
E) None of these choices.

Question 2

As we go down Group 7A of the periodic table,the size of the halogen atom increases; accordingly,the carbon-halogen bond length gets ___ and the bond strength gets ___.

Accepted Answer

The answer of As we go down Group 7A of...

Question 3

Which of these species,acting in a protic solvent,exhibits greater nucleophilic activity than expected on the basis of its basicity?

Accepted Answer

A) OH- 
B) CH3O- 
C) SH- 
D) Cl- 
E) H2O 
A) OH- 
B) CH3O- 
C) SH- 
D) Cl- 
E) H2O

Question 4

Which SN2 reaction will occur most rapidly in a mixture of water and ethanol?

Accepted Answer

A) I- + CH3CH2-Br $\to$ CH3CH2-I + Br- 
B) I- + CH3CH2-Cl $\to$ CH3CH2-I + Cl- 
C) I- + CH3CH2-F $\to$ CH3CH2-I + F- 
D) Br- + CH3CH2-Cl $\to$ CH3CH2-Br + Cl- 
E) Br- + CH3CH2-F $\to$ CH3CH2-Br + F- 
A) I- + CH3CH2-Br $\to$ CH3CH2-I + Br- 
B) I- + CH3CH2-Cl $\to$ CH3CH2-I + Cl- 
C) I- + CH3CH2-F $\to$ CH3CH2-I + F- 
D) Br- + CH3CH2-Cl $\to$ CH3CH2-Br + Cl- 
E) Br- + CH3CH2-F $\to$ CH3CH2-Br + F-

Question 5

Which of the following is not a good leaving group?

Accepted Answer

A) C2H5O- 
B) Cl- 
C) Isup>- 
D) CH3CO2- 
E) All of these choices are good leaving groups. 
A) C2H5O- 
B) Cl- 
C) Isup>- 
D) CH3CO2- 
E) All of these choices are good leaving groups.

Question 6

A reaction in which the nucleophile is a molecule of the solvent is referred to as a ___ reaction.

Accepted Answer

The answer of A reaction in which the nucleophile is...

Question 7

The relative nucleophilicities of species do not necessarily parallel the relative basicities of the same species because

Accepted Answer

A) not all nucleophiles are bases,and vice versa. 
B) experimental measurements of sufficient accuracy are not available to make the comparisons. 
C) nucleophilicity is a thermodynamic matter; basicity is a matter of kinetics. 
D) basicity is a thermodynamic matter; nucleophilicity is a matter of kinetics. 
E) Actually,the relative values do parallel one another. 
A) not all nucleophiles are bases,and vice versa. 
B) experimental measurements of sufficient accuracy are not available to make the comparisons. 
C) nucleophilicity is a thermodynamic matter; basicity is a matter of kinetics. 
D) basicity is a thermodynamic matter; nucleophilicity is a matter of kinetics. 
E) Actually,the relative values do parallel one another.

Question 8

Identify the leaving group in the following reaction.

Accepted Answer

A) CH3OH 
B) CH3OH2+ 
C) CH3OCH3 
D) H2O 
E) None of these choices. 
A) CH3OH 
B) CH3OH2+ 
C) CH3OCH3 
D) H2O 
E) None of these choices.

Question 9

Identify the nucleophile in the following reaction: 2R'OH + RX $\to$ ROR' + [R'OH2]+ + X-

Accepted Answer

A) X- 
B) [R'OH2]- 
C) ROR' 
D) R'OH 
E) RX 
A) X- 
B) [R'OH2]- 
C) ROR' 
D) R'OH 
E) RX

Question 10

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 11

Which of the following statements is (are)true of an SN2 reaction of (R)-2-bromobutane with hydroxide ion?

Accepted Answer

A) Doubling the hydroxide ion concentration would double the rate of the reaction.(Assume that all other experimental conditions are unchanged.) 
B) The major product would be (S)-2-butanol. 
C) Doubling the concentration of (R)-2-bromobutane would double the rate of the reaction.(Assume that all other experimental conditions are unchanged.) 
D) All of these choices. 
E) Two of these choices. 
A) Doubling the hydroxide ion concentration would double the rate of the reaction.(Assume that all other experimental conditions are unchanged.) 
B) The major product would be (S)-2-butanol. 
C) Doubling the concentration of (R)-2-bromobutane would double the rate of the reaction.(Assume that all other experimental conditions are unchanged.) 
D) All of these choices. 
E) Two of these choices.

Question 12

SN1 reactions of the following type: Nu:- + R-X $\to$ R-Nu + :X-
Are favored

Accepted Answer

A) by the use of tertiary substrates (as opposed to primary or secondary substrates). 
B) by increasing the concentration of the nucleophile. 
C) by increasing the polarity of the solvent. 
D) by use of a strong base. 
E) by more than one of these choices. 
A) by the use of tertiary substrates (as opposed to primary or secondary substrates). 
B) by increasing the concentration of the nucleophile. 
C) by increasing the polarity of the solvent. 
D) by use of a strong base. 
E) by more than one of these choices.

Question 13

Which alkyl chloride,though primary,is essentially unreactive in SN2 reactions?

Accepted Answer

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

Question 14

Which is the weakest nucleophile in polar protic solvents?

Accepted Answer

A) I- 
B) Br- 
C) Cl- 
D) F- 
E) All of these choices are equally strong nucleophiles,regardless of the type of solvent used. 
A) I- 
B) Br- 
C) Cl- 
D) F- 
E) All of these choices are equally strong nucleophiles,regardless of the type of solvent used.

Question 15

Increasing the concentration of either of the reactants of an SN2 reaction increases the rate of the reaction.The primary reason for this is that increasing the concentration increases ___.

Accepted Answer

the frequency of collisions be

Question 16

Which alkyl halide would you expect to react most slowly when heated in aqueous solution?

Accepted Answer

A) (CH3)3C-F 
B) (CH3)3C-Cl 
C) (CH3)3C-Br 
D) (CH3)3C-I 
E) All of these choices would react at the same rate. 
A) (CH3)3C-F 
B) (CH3)3C-Cl 
C) (CH3)3C-Br 
D) (CH3)3C-I 
E) All of these choices would react at the same rate.

Question 17

The relative nucleophilicity of the halide ions in polar aprotic solvents is observed to be markedly different from that in protic solvents.Explain briefly.

Accepted Answer

The smaller,more highly electronegative

Question 18

A nucleophile in an SN2 reaction must approach from the ___ of the carbon atom attached to the leaving group since the electrons in the nucleophile's HOMO begins to overlap with the ___ of the carbon atom attached to the leaving group.

Accepted Answer

Question 19

Which SN2 reaction will occur most rapidly in aqueous acetone solution? Assume concentrations and temperature are the same in each instance.

Accepted Answer

A) HO- + CH3-Cl $\to$ CH3OH + Cl- 
B) HO- + CH3CH2-Cl $\to$ CH3CH2OH + Cl- 
C) HO- + (CH3)2CH-Cl $\to$ (CH3)2CHOH + Cl- 
D) HO- + (CH3)3C-Cl $\to$ (CH3)3COH + Cl- 
E) HO- + (CH3)3CCH2-Cl $\to$  (CH3)3CCH2OH + Cl- 
A) HO- + CH3-Cl $\to$ CH3OH + Cl- 
B) HO- + CH3CH2-Cl $\to$ CH3CH2OH + Cl- 
C) HO- + (CH3)2CH-Cl $\to$ (CH3)2CHOH + Cl- 
D) HO- + (CH3)3C-Cl $\to$ (CH3)3COH + Cl- 
E) HO- + (CH3)3CCH2-Cl $\to$  (CH3)3CCH2OH + Cl-

Question 20

Consider the substitution reaction that takes place when (R)-3-bromo-3-methylhexane is treated with methanol.Which of the following would be true?

Accepted Answer

A) The reaction would take place only with inversion of configuration at the stereogenic center. 
B) The reaction would take place only with retention of configuration at the stereogenic center. 
C) The reaction would take place with racemization. 
D) No reaction would take place. 
E) The alkyl halide does not possess a stereogenic center. 
A) The reaction would take place only with inversion of configuration at the stereogenic center. 
B) The reaction would take place only with retention of configuration at the stereogenic center. 
C) The reaction would take place with racemization. 
D) No reaction would take place. 
E) The alkyl halide does not possess a stereogenic center.

Exam 6: Nucleophilic Reactions

Which of the following is a feasible substitution reaction?

As we go down Group 7A of the periodic table,the size of the halogen atom increases; accordingly,the carbon-halogen bond length gets ___ and the bond strength gets ___.

Which of these species,acting in a protic solvent,exhibits greater nucleophilic activity than expected on the basis of its basicity?

Which SN2 reaction will occur most rapidly in a mixture of water and ethanol?

Which of the following is not a good leaving group?

A reaction in which the nucleophile is a molecule of the solvent is referred to as a ___ reaction.

The relative nucleophilicities of species do not necessarily parallel the relative basicities of the same species because

Identify the leaving group in the following reaction.

Identify the nucleophile in the following reaction: 2R'OH + RX →\to→ ROR' + [R'OH2]+ + X-

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

Which of the following statements is (are)true of an SN2 reaction of (R)-2-bromobutane with hydroxide ion?

SN1 reactions of the following type: Nu:- + R-X →\to→ R-Nu + :X- Are favored

Which alkyl chloride,though primary,is essentially unreactive in SN2 reactions?

Which is the weakest nucleophile in polar protic solvents?

Increasing the concentration of either of the reactants of an SN2 reaction increases the rate of the reaction.The primary reason for this is that increasing the concentration increases ___.

Which alkyl halide would you expect to react most slowly when heated in aqueous solution?

The relative nucleophilicity of the halide ions in polar aprotic solvents is observed to be markedly different from that in protic solvents.Explain briefly.

A nucleophile in an SN2 reaction must approach from the ___ of the carbon atom attached to the leaving group since the electrons in the nucleophile's HOMO begins to overlap with the ___ of the carbon atom attached to the leaving group.

Which SN2 reaction will occur most rapidly in aqueous acetone solution? Assume concentrations and temperature are the same in each instance.

Consider the substitution reaction that takes place when (R)-3-bromo-3-methylhexane is treated with methanol.Which of the following would be true?

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

As we go down Group 7A of the periodic table,the size of the halogen atom increases; accordingly,the carbon-halogen bond length gets _ and the bond strength gets _.

Which S_N2 reaction will occur most rapidly in a mixture of water and ethanol?

Identify the nucleophile in the following reaction: 2R'OH + RX $\to$ ROR' + [R'OH₂]⁺ + X^-

Which of the following statements is (are)true of an S_N2 reaction of (R)-2-bromobutane with hydroxide ion?

S_N1 reactions of the following type: Nu:^- + R-X $\to$ R-Nu + :X^- Are favored

Which alkyl chloride,though primary,is essentially unreactive in S_N2 reactions?

Increasing the concentration of either of the reactants of an S_N2 reaction increases the rate of the reaction.The primary reason for this is that increasing the concentration increases ___.

A nucleophile in an S_N2 reaction must approach from the _ of the carbon atom attached to the leaving group since the electrons in the nucleophile's HOMO begins to overlap with the _ of the carbon atom attached to the leaving group.

Which S_N2 reaction will occur most rapidly in aqueous acetone solution? Assume concentrations and temperature are the same in each instance.