Question 1

Which of the following statements about the carbonyl group in aldehydes and ketones is INCORRECT?

Accepted Answer

The $$\pi$$ electrons are mobile and are pulled toward the carbonyl carbon.

Question 2

Arrange the following compounds in order of increasing boiling point: butane, butanol, butanone.

Accepted Answer

Butane \u003c butanone \u003c butanol

Question 3

What is the product when propanone reacts with one equivalent of ethanol under acidic conditions?

Accepted Answer

A hemiketal: $$\mathrm{CH_3C(OH)(OC_2H_5)CH_3$}$$

Question 4

Which of the following best explains why aldehydes are generally more reactive toward nucleophilic attack than ketones?

Accepted Answer

Aldehydes have less steric hindrance and fewer electron-donating alkyl groups than ketones.

Question 5

Which reagent can oxidize an aldehyde to a carboxylic acid, but NOT a ketone?

Accepted Answer

$$\mathrm{$$KMnO_4$$}$$

Question 6

A student wants to synthesize an aldehyde from a primary alcohol without further oxidation to a carboxylic acid. Which reagent should be used?

Accepted Answer

$$\mathrm{PCC}$$

Question 7

Which of the following is the major product when hydrogen cyanide reacts with butyraldehyde?

Accepted Answer

A cyanohydrin: $$\mathrm{CH_3CH_2CH(OH)CN}$$

Question 8

Which of the following best describes the mechanism of nucleophilic addition to a carbonyl group?

Accepted Answer

The nucleophile attacks the carbonyl carbon, breaking the $$\pi$$ bond and pushing electrons onto oxygen.

Question 9

Which of the following is TRUE regarding the physical properties of aldehydes and ketones?

Accepted Answer

Aldehydes and ketones have higher boiling points than alkanes due to dipole-dipole interactions.

Question 10

Which of the following is a product when an aldehyde reacts with excess alcohol under acidic conditions?

Accepted Answer

An acetal

Question 11

Which of the following compounds can be reduced to a secondary alcohol using $$\mathrm{$$LiAlH_4$$}$$?

Accepted Answer

A ketone

Question 12

What is the product when ammonia reacts with glutaraldehyde?

Accepted Answer

An imine

Question 13

Which of the following statements about hemiacetals and hemiketals is CORRECT?

Accepted Answer

They are generally unstable and tend to react further to form acetals and ketals.

Question 14

Which of the following could attack a carbonyl carbon to form a geminal diol?

Accepted Answer

Water

Question 15

Which of the following describes pyridinium chlorochromate (PCC)?

Accepted Answer

An oxidant that can form aldehydes from primary alcohols and oxidize secondary alcohols to ketones.

Question 16

Which of the following is the correct structure of a hemiketal?

Accepted Answer

A carbon bonded to one $$-OH$$, one $$-OR$$, and two $$-R$$ groups

Question 17

Which of the following is a common real-world application of nucleophilic addition to carbonyls?

Accepted Answer

Formation of imines in biological nitrogen metabolism

Question 18

Which of the following can be used to reduce a ketone to a secondary alcohol?

Accepted Answer

$$\mathrm{$$LiAlH_4$$}$$

Question 19

Imines naturally tautomerize to form which of the following?

Accepted Answer

Enamines

Kaplan ch 6

Study Guide - Practice Questions