Question 1

Which of the following statements best explains why tertiary alkyl halides undergo SN1 reactions more readily than primary alkyl halides?

Accepted Answer

Tertiary alkyl halides form more stable carbocations due to greater alkyl substitution, stabilizing the intermediate.

Question 2

Consider the reaction: $$\mathrm{CH_3CH_2Br}$$ reacts with $$\mathrm{NaOH} in $$DMSO. Which mechanism is most likely and why?

Accepted Answer

SN2, because DMSO is a polar aprotic solvent and $$\mathrm{CH_3CH_2Br} is a $$primary alkyl halide.

Question 3

Which of the following is the best leaving group for a nucleophilic substitution reaction?

Accepted Answer

$$\mathrm{I^-}$$

Question 4

A student treats 2-bromopropane with water. Which of the following statements about the reaction is correct?

Accepted Answer

The reaction proceeds via an SN1 mechanism, and the product is racemic.

Question 5

Which of the following solvents would most likely increase the rate of an SN2 reaction?

Accepted Answer

Dimethyl sulfoxide (DMSO)

Question 6

Which of the following statements about E2 eliminations on cyclohexane rings is correct?

Accepted Answer

The leaving group and the hydrogen must be anti-periplanar (trans-diaxial) to each other.

Question 7

Which of the following best describes the product(s) of the reaction of 1-butene with $$\mathrm{HBr} in $$the presence of peroxides?

Accepted Answer

1-bromobutane, via anti-Markovnikov addition

Question 8

Which of the following is the correct IUPAC name for the compound shown below?

$$\mathrm{CH_3CH_2CBr(CH_3$)_2}$$

Accepted Answer

2-bromo-2-methylbutane

Question 9

Which of the following statements about the hydroboration-oxidation of alkenes is correct?

Accepted Answer

It results in anti-Markovnikov addition of water with syn stereochemistry.

Question 10

Which of the following best explains why $$\mathrm{I^-} is a $$better nucleophile than $$\mathrm{F^-} in $$polar aprotic solvents?

Accepted Answer

$$\mathrm{I^-} is $$less basic and more polarizable, making it more reactive in polar aprotic solvents.

Question 11

A chemist wants to synthesize trans-2-butene from 2-butyne. Which set of reagents should be used?

Accepted Answer

Na/NH$$_3 ($$sodium in liquid ammonia)

Question 12

Which of the following is true regarding the stereochemistry of SN2 reactions?

Accepted Answer

The configuration at the reacting center is inverted.

Question 13

Which of the following best describes the product of the acid-catalyzed hydration of 1-methylcyclohexene?

Accepted Answer

The alcohol adds to the more substituted carbon (Markovnikov).

Question 14

Which of the following statements about the E1 elimination mechanism is correct?

Accepted Answer

It involves carbocation intermediates and can undergo rearrangement.

Question 15

Which of the following is the correct order of nucleophilicity in polar aprotic solvents?

Accepted Answer

$$\mathrm{I^-} \u003e \mathrm{Br^-} \u003e \mathrm{Cl^-} \u003e \mathrm{F^-}$$

Question 16

Which of the following reactions will produce a racemic mixture of enantiomers?

Accepted Answer

SN1 reaction of (S)-2-bromobutane with water

Question 17

Which of the following best describes the product of the reaction of 2-methyl-2-butene with $$\mathrm{Br_2$} in $$water?

Accepted Answer

A bromohydrin, with Br and OH added anti to each other

Question 18

Which of the following is the correct IUPAC name for the compound with the structure $$\mathrm{CH_3C \equiv CCH_2CH_3}$$?

Accepted Answer

2-pentyne

Question 19

Which of the following statements about Markovnikov's rule is correct?

Accepted Answer

The hydrogen atom adds to the carbon with the most hydrogens already attached.

Comprehensive Study Guide: Alkyl Halides, Alkenes, and Alkynes (Chapters 6–9)

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