Question 1

Which of the following best describes the mechanism of epoxide ring opening under basic conditions?

Accepted Answer

The nucleophile attacks the less substituted carbon of the epoxide.

Question 2

In the reaction of an epoxide with sodium methoxide ($$\mathrm{$$NaOCH_3$$}) in $$methanol, what is the major product?

Accepted Answer

A methoxy alcohol with the methoxy group added to the less substituted carbon.

Question 3

Which of the following is a key characteristic of nucleophilic addition to carbonyl compounds under acidic conditions?

Accepted Answer

The nucleophile attacks after the carbonyl is protonated.

Question 4

What is the product of the reaction between cyclohexanone and sodium cyanide ($$\mathrm{NaCN}) in $$water?

Accepted Answer

Cyclohexanone cyanohydrin

Question 5

Which of the following statements about the reactivity of epoxides is correct?

Accepted Answer

Epoxides are more reactive than ethers due to ring strain.

Question 6

During nucleophilic addition to a carbonyl group, which factor most increases the electrophilicity of the carbonyl carbon?

Accepted Answer

Protonation of the carbonyl oxygen

Question 7

Which of the following nucleophiles would react fastest with a ketone under basic conditions?

Accepted Answer

$$\mathrm{NaCN}$$

Question 8

A student reacts propanone (acetone) with methanol in the presence of acid. What is the major product?

Accepted Answer

A hemiacetal

Question 9

Which of the following best explains why nucleophilic addition to aldehydes is generally faster than to ketones?

Accepted Answer

Aldehydes are less sterically hindered and more electrophilic.

Question 10

Which of the following is the correct order of reactivity toward nucleophilic addition: formaldehyde, acetone, benzaldehyde?

Accepted Answer

Formaldehyde \u003e Benzaldehyde \u003e Acetone

Question 11

Which of the following best describes the product of the reaction between an epoxide and ammonia ($$\mathrm{NH_3$}) $$under basic conditions?

Accepted Answer

A primary amine with the amino group on the less substituted carbon

Question 12

Which of the following is a common misconception about the mechanism of nucleophilic addition to carbonyls under acidic conditions?

Accepted Answer

The nucleophile attacks before the carbonyl is protonated.

Question 13

Which of the following best describes the role of acid in the hydration of an aldehyde?

Accepted Answer

It protonates the carbonyl oxygen, increasing electrophilicity.

Question 14

Which of the following is the correct product for the reaction of ethylene oxide with sodium azide ($$\mathrm{$$NaN_3$$}) in $$water?

Accepted Answer

1-Azidoethanol

Question 15

Which of the following statements about the reaction of epoxides with strong nucleophiles is correct?

Accepted Answer

The nucleophile attacks the less substituted carbon.

Question 16

Which of the following is the best explanation for why epoxides are more reactive than ethers?

Accepted Answer

Epoxides have significant ring strain, making them more reactive.

Question 17

A chemist wants to synthesize a 1,2-diol from an alkene. Which sequence of reactions would be most appropriate?

Accepted Answer

Epoxidation followed by acid-catalyzed ring opening

Question 18

Which of the following is the correct mechanism for the reaction of an epoxide with water under acidic conditions?

Accepted Answer

Protonation of the epoxide oxygen, followed by nucleophilic attack by water at the more substituted carbon

Question 19

Which of the following best describes the product of the reaction between benzaldehyde and sodium bisulfite ($$\mathrm{$$NaHSO_3$$}$$)?

Accepted Answer

A bisulfite adduct

Epoxide Formation and Carbonyl Addition Reactions: Mechanisms and Conditions

Study Guide - Practice Questions