Question 1

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

Accepted Answer

Aldehydes are less sterically hindered and have only one electron-donating group, making the carbonyl carbon more electrophilic.

Question 2

What is the correct IUPAC name for the following compound: $$\mathrm{CH_3CH_2COCH_3}$$?

Accepted Answer

2-Butanone

Question 3

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

Accepted Answer

The carbonyl oxygen is protonated first, increasing the electrophilicity of the carbonyl carbon, then the nucleophile attacks.

Question 4

Which of the following is a correct statement about hydrate formation from aldehydes and ketones?

Accepted Answer

Hydrate formation is generally favored for very simple aldehydes at equilibrium.

Question 5

A chemist wants to protect a ketone functional group during a multi-step synthesis. Which of the following strategies is most appropriate?

Accepted Answer

Convert the ketone to an acetal by reacting it with an alcohol and acid catalyst, then remove water.

Question 6

Which of the following reagents will reduce both aldehydes and ketones to their corresponding alcohols, but must be used in anhydrous ether solvents due to its reactivity with water?

Accepted Answer

Lithium aluminum hydride ($$\mathrm{$$LiAlH_4$$})$$

Question 7

Which of the following best describes the product of the reaction between a ketone and a primary amine under mildly acidic conditions?

Accepted Answer

An imine

Question 8

A student attempts to perform a Grignard reaction using $$\mathrm{CH_3MgBr}$$ and acetone in water as the solvent. What is the most likely outcome?

Accepted Answer

The Grignard reagent will react with water to form methane, and no addition to acetone will occur.

Question 9

Which of the following statements about acetal formation is correct?

Accepted Answer

Acetal formation is reversible and can be driven to completion by removing water from the reaction mixture.

Question 10

Which of the following best explains why sodium borohydride ($$\mathrm{$$NaBH_4$$}) $$and lithium aluminum hydride ($$\mathrm{$$LiAlH_4$$}) do $$not reduce carbon-carbon double bonds, while catalytic hydrogenation does?

Accepted Answer

They are selective for polar C=O bonds and do not react with nonpolar C=C bonds.

Question 11

Which of the following is the correct mechanism for the formation of a cyanohydrin from a ketone under basic conditions?

Accepted Answer

The cyanide ion attacks the carbonyl carbon, followed by protonation of the oxygen.

Question 12

Which of the following best describes the structure of an acetal?

Accepted Answer

A carbon atom bonded to two alkoxy groups ($$\mathrm{RO}) $$and either two carbons or one carbon and one hydrogen.

Question 13

Which of the following is a correct statement about the reversibility of imine and acetal formation?

Accepted Answer

Both imine and acetal formation are reversible and can be driven in either direction by adding or removing water.

Question 14

A chemist is performing an aldol addition between acetaldehyde and itself under basic conditions. What is the major product?

Accepted Answer

$$\mathrm{CH_3CH(OH)CH_2CHO}$$

Question 15

Which of the following best describes the role of pH in imine formation from a ketone and a primary amine?

Accepted Answer

Imine formation is fastest at intermediate pH (pH 4-5) because there is enough acid to catalyze the reaction but not so much that all amines are protonated.

Question 16

Which of the following statements about enolate formation is correct?

Accepted Answer

Enolates are formed by deprotonation of the alpha carbon of a carbonyl compound.

Question 17

Which of the following is a correct statement about the selectivity of hydride reductions using $$\mathrm{$$NaBH_4$$} or$$ $$\mathrm{$$LiAlH_4$$}$$?

Accepted Answer

They selectively reduce carbonyl groups but do not reduce isolated C=C double bonds.

Question 18

Which of the following best describes the product of the reaction between a Grignard reagent and a ketone, followed by aqueous workup?

Accepted Answer

A tertiary alcohol

Question 19

Which of the following is the correct order of steps for naming an aldehyde according to IUPAC nomenclature?

Accepted Answer

Identify the parent chain, name substituents, assign locants, assemble the name alphabetically.

Aldehydes and Ketones: Structure, Reactivity, and Nucleophilic Addition Reactions

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