Question 1

Which of the following statements best explains why ethers have lower boiling points than their isomeric alcohols?

Accepted Answer

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

Question 2

Which method is most suitable for synthesizing an ether from a primary alkyl halide and an alcohol?

Accepted Answer

Williamson ether synthesis

Question 3

What is the major product when diethyl ether is heated with excess HI?

Accepted Answer

$$2\mathrm{C_2H_5I}$$ \, and \, \mathrm{H_2O}$

Question 4

Which of the following best describes the role of tetrahydrofuran (THF) in the formation of Grignard reagents?

Accepted Answer

THF stabilizes the Grignard reagent by coordinating to the metal center.

Question 5

A compound with the formula $$\mathrm{C_4H_8O}$$ shows a $$^1\mathrm{H}$$ NMR signal at $$\delta 2.5$-3.0$\,$$ppm and no signals above $$\delta 4.0$\,$$ppm. Which structure is most consistent with this data?

Accepted Answer

Tetrahydrofuran

Question 6

Which of the following is the correct IUPAC name for the compound commonly known as 'methyl tert-butyl ether'?

Accepted Answer

2-Methoxy-2-methylpropane

Question 7

What is the main fragmentation observed in the mass spectrum of ethers?

Accepted Answer

Alpha cleavage to form a resonance-stabilized oxonium ion

Question 8

Which of the following best describes the selectivity of crown ethers for metal cations?

Accepted Answer

The selectivity depends on the size of the ether ring, which matches the ionic radius of the cation.

Question 9

Which of the following statements about the acid-catalyzed opening of epoxides is correct?

Accepted Answer

The nucleophile attacks the more substituted carbon atom due to carbocation stabilization.

Question 10

Which reagent is commonly used to convert an alkene to an epoxide in a single step?

Accepted Answer

meta-Chloroperoxybenzoic acid (MCPBA)

Question 11

Which of the following is a correct statement about the physical properties of ethers?

Accepted Answer

Ethers are generally more soluble in water than alkanes of similar molecular weight.

Question 12

What is the product of the reaction between ethylene oxide and methylmagnesium bromide followed by aqueous workup?

Accepted Answer

$$\mathrm{CH_3CH_2CH_2OH}$$

Question 13

Which of the following best explains why ethers are used as solvents for Grignard reactions?

Accepted Answer

Ethers stabilize the Grignard reagent by coordinating to the magnesium atom.

Question 14

Which of the following is a correct IUPAC name for the compound shown below?

$$\mathrm{CH_3CH_2OCH_2CH_3}$$

Accepted Answer

Ethoxyethane

Question 15

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

Accepted Answer

Thioethers are oxidized to sulfoxides and then to sulfones.

Question 16

Which of the following best describes the mechanism of the Williamson ether synthesis?

Accepted Answer

SN2 attack of an alkoxide ion on a primary alkyl halide

Question 17

What is the expected product when 1,2-epoxypropane is treated with sodium methoxide in methanol?

Accepted Answer

Methoxy group adds to the less substituted carbon

Question 18

Which of the following is a correct statement about the autoxidation of ethers?

Accepted Answer

Ethers slowly oxidize in air to form hydroperoxides and dialkyl peroxides.

Question 19

Which of the following best describes the product of the reaction between a thioether and an unhindered alkyl halide?

Accepted Answer

A sulfonium salt

Question 20

Which of the following is the correct order of reactivity for the cleavage of ethers by hydrogen halides?

Accepted Answer

$$\mathrm{HI \u003e HBr \u003e HCl}$$

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

Guida di studio - Domande di pratica

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