NUCLEOPHILIC SUBSTITUTION
(Quiz 6-1)

1. The reaction of methyl iodide with sodium azide, NaN₃, proceeds by an S_N2 mechanism. What is the effect of doubling the concentration of NaN₃ on the rate of the reaction?

(A) the rate remains the same

(B) the rate decreases by a factor of 2

(C) the rate increases by a factor of 2

(D) the rate increases by a factor of 4

2.Which of the following alkyl halides undergoes the fastest S_N2 reaction with sodium azide, NaN₃?

(A) 1-fluorohexane

(B) 1-chlorohexane

(C) 1-bromohexane

(D) 1-iodohexane

3. Which of the following alkyl halides undergoes the fastest solvolysis reaction with formic acid, HCOOH?

(A) tert-butyl fluoride

(B) tert-butyl chloride

(C) tert-butyl bromide

(D) tert-butyl iodide

4. What is the major organic product obtained from the following reaction?

(A) 1

(B) 2

(C) 3

(D) 4

5. In which of the following solvents would the reaction of 1-bromobutane with sodium azide, NaN₃, proceed the fastest?

(A) acetic acid

(B) ethanol

(C) water

(D) acetonitrile

6. Which of the following anions is the most nucleophilc in polar aprotic solvents?

(A) F^-

(B) Cl^-

(C) Br^-

(D) I^-

7. Which of the following statements is not true regarding the S_N2 reaction of (R)-2-bromobutane with sodium cyanide?

(A) the reaction proceeds with inversion of configuration

(B) the rate is proportional to the concentration of sodium cyanide

(C) the rate is proportional to the concentration of (R)-2-bromobutane

(D) the rate of the reaction is independent of the identity of the solvent

8. Which of the following represents the transition state of the reaction between methyl iodide sodium methylthiolate, NaSCH₃?

(A) 1

(B) 2

(C) 3

(D) 4

9. Which of the following energy diagrams represents the course of an exothermic S_N1 reaction?

(A) 1

(B) 2

(C) 3

(D) 4

10. Which of the following sets consists of only polar aprotic solvents?

(A) water, hexane, methanol

(B) acetic acid, DMF, toluene

(C) DMSO, ethanol, acetonitrile

(D) DMF, acetonitrile, DMSO