Question 1

Which of the following statements best explains why bromination of alkanes is more selective than chlorination during radical halogenation?

Accepted Answer

Bromine radicals are less reactive and require higher activation energy, favoring abstraction of the most stable hydrogen.

Question 2

Which of the following alkyl halides would react fastest in an $$\mathrm{S_N1}$$ reaction in water?

Accepted Answer

tert-Butyl bromide ($$\mathrm{(CH_3$)_3CBr})$$

Question 3

A student treats 2-butanol with $$\mathrm{$$SOCl_2$$}. $$What is the major organic product?

Accepted Answer

2-Chlorobutane ($$\mathrm{CH_3CHClCH_2CH_3})$$

Question 4

Which of the following best describes the effect of polar aprotic solvents (e.g., DMSO, DMF) on $$\mathrm{S_N2}$$ reactions?

Accepted Answer

They increase the nucleophilicity of the nucleophile, accelerating the $$\mathrm{S_N2}$$ reaction.

Question 5

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

Accepted Answer

$$\mathrm{I^-}$$

Question 6

A chemist wants to synthesize a Grignard reagent. Which combination of reagents and conditions is most appropriate?

Accepted Answer

Reacting an alkyl bromide with magnesium metal in dry ether

Question 7

Which of the following statements about the acidity of phenol compared to ethanol is correct?

Accepted Answer

Phenol is more acidic because its conjugate base is stabilized by resonance delocalization.

Question 8

Which of the following best explains why tertiary alcohols react faster with $$\mathrm{HX} to $$form alkyl halides than primary alcohols?

Accepted Answer

Tertiary carbocations are more stable, facilitating the $$\mathrm{S_N1}$$ mechanism.

Question 9

Which of the following is the correct rate law for an $$\mathrm{S_N2}$$ reaction?

Accepted Answer

$$\mathrm{rate = k[substrate][nucleophile]}$$

Question 10

A chemist treats 1-bromopropane with sodium cyanide ($$\mathrm{NaCN}) in $$DMSO. What is the expected major product?

Accepted Answer

Butanenitrile ($$\mathrm{CH_3CH_2CH_2CN})$$

Question 11

Which of the following statements about the Walden inversion is correct?

Accepted Answer

It refers to the inversion of stereochemistry during an $$\mathrm{S_N2}$$ reaction.

Question 12

Which of the following best explains why tosylates are excellent leaving groups in substitution reactions?

Accepted Answer

The tosylate anion is stabilized by resonance and is a weak base.

Question 13

Which of the following statements about nucleophilicity trends in the halide series is correct?

Accepted Answer

$$\mathrm{I^-} is a $$better nucleophile than $$\mathrm{F^-} in $$polar aprotic solvents.

Question 14

A chemist wants to convert an alcohol to an alkyl bromide without using strong acid. Which reagent is most suitable?

Accepted Answer

$$\mathrm{$$PBr_3$$}$$

Question 15

Which of the following best describes the effect of electron-withdrawing groups on the acidity of phenols?

Accepted Answer

They increase acidity by stabilizing the phenoxide ion.

Question 16

Which of the following is a correct statement about the preparation of ethers via solvolysis of alkyl halides?

Accepted Answer

It typically proceeds via an $$\mathrm{S_N1}$$ mechanism in the presence of water.

Question 17

Which of the following best explains why alcohols have higher boiling points than alkanes of similar molecular weight?

Accepted Answer

Alcohols form hydrogen bonds, which require more energy to break.

Question 18

A chemist wants to protect an alcohol group during a multi-step synthesis. Which reagent is most appropriate?

Accepted Answer

Trimethylsilyl chloride ($$\mathrm{TMSCl})$$

Question 19

Which of the following best describes the product(s) of allylic bromination of 1-butene with NBS and light?

Accepted Answer

A mixture of 3-bromo-1-butene and 1-bromo-2-butene due to resonance-stabilized allylic radicals

Question 20

Which of the following statements about organocuprates ($$\mathrm{R_2CuLi}) is $$correct?

Accepted Answer

They are softer nucleophiles than Grignard reagents and can couple with primary alkyl halides to form C–C bonds.

Study Guide: Organohalides, Alkyl Halide Reactions, Alcohols & Phenols

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