Question 1

Which of the following statements best explains why ethanol ($$\mathrm{C_2H_5OH}) is $$miscible with water, while decanol ($$\mathrm{C$$_{10}$$H_{21}OH$$}$) is not?

Accepted Answer

Ethanol forms stronger hydrogen bonds with water due to its shorter hydrocarbon chain, making it more soluble.

Question 2

Which reagent is most suitable for the selective reduction of an aldehyde to a primary alcohol without affecting an ester group in the same molecule?

Accepted Answer

$$\mathrm{$$NaBH_4$$}$$

Question 3

What is the major product when butanal ($$\mathrm{CH_3CH_2CH_2CHO}) is $$treated with $$\mathrm{$$NaBH_4$$} in $$ethanol followed by $$\mathrm{H_3O^+}$$?

Accepted Answer

$$\mathrm{CH_3CH_2CH_2CH_2OH} ($$butan-1-ol)

Question 4

Which of the following best describes the mechanism for the reduction of a ketone to a secondary alcohol using $$\mathrm{$$NaBH_4$$}$$?

Accepted Answer

Nucleophilic addition of hydride to the carbonyl carbon, followed by protonation of the alkoxide intermediate.

Question 5

Which of the following statements about the oxidation of alcohols is correct?

Accepted Answer

Primary alcohols can be oxidized to aldehydes or carboxylic acids, depending on the conditions.

Question 6

Which reagent is commonly used to selectively oxidize a primary alcohol to an aldehyde without further oxidation to a carboxylic acid?

Accepted Answer

Pyridinium chlorochromate (PCC)

Question 7

Which of the following best explains the high boiling points of alcohols compared to alkanes of similar molecular weight?

Accepted Answer

Alcohols form intermolecular hydrogen bonds due to the presence of the $$-\mathrm{OH}$$ group.

Question 8

Which of the following is a limitation of the Friedel–Crafts alkylation reaction?

Accepted Answer

Polyalkylation can occur, leading to multiple substitutions.

Question 9

Why does Friedel–Crafts acylation typically avoid poly-substitution on the aromatic ring?

Accepted Answer

The acyl group is deactivating, making the ring less reactive toward further substitution.

Question 10

Which of the following best describes the electronic structure of benzene?

Accepted Answer

A continuous delocalized $$\pi-$$electron system formed by the overlap of six $$p-$$orbitals.

Question 11

Which of the following is the correct order of reactivity toward nucleophilic addition: aldehydes, ketones, esters, carboxylic acids?

Accepted Answer

Aldehydes \u003e ketones \u003e esters \u003e carboxylic acids

Question 12

Which of the following is a characteristic reaction of benzene?

Accepted Answer

Electrophilic aromatic substitution

Question 13

What is the electrophile in the nitration of benzene?

Accepted Answer

Nitronium ion ($$\mathrm{NO_2$^+})$$

Question 14

Which of the following statements about the reduction of carboxylic acids and esters is correct?

Accepted Answer

Both are reduced to primary alcohols, typically using $$\mathrm{$$LiAlH_4$$}.$$

Question 15

A chemist wants to convert a secondary alcohol to a ketone. Which reagent should they use?

Accepted Answer

$$\mathrm{K_2Cr_2O_7} in$$ $$\mathrm{H_2SO_4}$$

Question 16

Which of the following is a reason why phenols are more acidic than alcohols?

Accepted Answer

The phenoxide ion is stabilized by resonance with the aromatic ring.

Question 17

Which of the following is a real-world application of the Friedel–Crafts acylation reaction?

Accepted Answer

Synthesis of aromatic ketones used as intermediates in drug molecules.

Question 18

Which of the following statements about the conversion of alcohols to alkyl halides is correct?

Accepted Answer

Primary and secondary alcohols are best converted to alkyl halides using $$\mathrm{$$SOCl_2$$} or$$ $$\mathrm{$$PCl_5$$}.$$

Alcohols, Phenols, and Aromatic Compounds: Structure, Reactivity, and Key Transformations

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