Question 1

Which of the following statements best explains why ethers have lower boiling points than alcohols of similar molecular weight?

Accepted Answer

Ethers cannot form hydrogen bonds with each other, while alcohols can.

Question 2

Which of the following compounds would be most soluble in diethyl ether?

Accepted Answer

Naphthalene (a nonpolar aromatic hydrocarbon)

Question 3

What is the IUPAC name for the compound shown below?

$$\mathrm{CH_3OCH_2CH_2CH_3}$$

Accepted Answer

1-Methoxypropane

Question 4

Which of the following best describes the role of ethers in Grignard reagent solutions?

Accepted Answer

Ethers stabilize the Grignard reagent by coordinating to the magnesium atom with their lone pairs.

Question 5

Which of the following is a correct statement about the Williamson ether synthesis?

Accepted Answer

It is most efficient when the alkyl halide is primary and unhindered.

Question 6

A student attempts to synthesize tert-butyl propyl ether using sodium propoxide and tert-butyl bromide. What is the major product of this reaction?

Accepted Answer

Isobutylene (2-methylpropene)

Question 7

Which of the following best explains why phenol cannot be converted to a phenyl halide by reaction with HBr?

Accepted Answer

An $$\mathrm{S_N2}$$ reaction cannot occur on an sp$$^2$$ carbon.

Question 8

Which of the following statements about crown ethers is correct?

Accepted Answer

Crown ethers can solvate metal cations, allowing inorganic salts to dissolve in nonpolar organic solvents.

Question 9

Which IR absorption would indicate the presence of an ether but not an alcohol or carbonyl compound?

Accepted Answer

A strong absorption in the 1000–1200 cm$$^{-1}$$ region with no broad O–H or C=O stretch.

Question 10

Which of the following is a product of the acid-catalyzed cleavage of diethyl ether with excess HI?

Accepted Answer

$$\mathrm{2\ HI + CH_3CH_2OCH_2CH_3 \rightarrow 2\ CH_3CH_2I + H_2O}$$

Question 11

Which of the following best describes the mechanism for the formation of an epoxide from a halohydrin?

Accepted Answer

An internal $$\mathrm{S_N2}$$ reaction where the alkoxide displaces the halide ion.

Question 12

Which of the following reagents is commonly used to convert an alkene to an epoxide?

Accepted Answer

meta-Chloroperoxybenzoic acid (MCPBA)

Question 13

When an epoxide is treated with a strong base such as sodium ethoxide, which carbon does the nucleophile attack?

Accepted Answer

The less hindered (less substituted) carbon of the epoxide ring.

Question 14

Which of the following is a correct statement about the oxidation of thioethers (sulfides)?

Accepted Answer

Thioethers can be oxidized to sulfoxides and further to sulfones.

Question 15

Which of the following best explains why silyl ethers are used as protecting groups for alcohols in organic synthesis?

Accepted Answer

Silyl ethers are resistant to many acids, bases, and oxidizing agents, and can be easily removed.

Question 16

Which of the following is a likely product when a Grignard reagent reacts with an epoxide?

Accepted Answer

An alcohol with two additional carbon atoms compared to the Grignard reagent's alkyl group.

Question 17

Which of the following is a safety concern when working with ethers in the laboratory?

Accepted Answer

Ethers can form explosive peroxides upon exposure to air.

Question 18

Which of the following best describes the product of the acid-catalyzed opening of an epoxide in methanol?

Accepted Answer

An alkoxy alcohol with anti stereochemistry.

Ethers, Epoxides, and Thioethers: Structure, Properties, and Reactions

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