Tetrahedral with a bond angle of $$110^\\circ$$

Question 1

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

Accepted Answer

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

Question 2

What is the molecular geometry around the oxygen atom in an ether such as diethyl ether?

Accepted Answer

Tetrahedral with a bond angle of $$110^\circ$$

Question 3

Which of the following is a correct example of a symmetrical ether?

Accepted Answer

Diethyl ether ($$CH_3CH_2OCH_2CH_3)$$

Question 4

Why are ethers commonly used as solvents in reactions involving strong bases?

Accepted Answer

Ethers are unreactive toward strong bases and can dissolve both polar and nonpolar substances.

Question 5

Which of the following statements about the Williamson ether synthesis is correct?

Accepted Answer

It involves an $$S_N2$$ attack of an alkoxide ion on an unhindered primary alkyl halide or tosylate.

Question 6

Which reagent is commonly used to convert alkenes to epoxides?

Accepted Answer

meta-chloroperoxybenzoic acid (MCPBA)

Question 7

What is the major product when an epoxide is opened under acid-catalyzed conditions?

Accepted Answer

A trans-1,2-diol, with nucleophilic attack at the more substituted carbon.

Question 8

Which of the following statements about thioethers (sulfides) is true?

Accepted Answer

Thioethers are easily oxidized to sulfoxides and sulfones.

Question 9

What is the role of silyl ethers in organic synthesis?

Accepted Answer

They are used as protecting groups for alcohols, making them resistant to some acids, bases, and oxidizing agents.

Question 10

Which of the following best describes the selectivity of epoxidation with peroxyacids?

Accepted Answer

The most electron-rich double bond reacts fastest, allowing selective epoxidation.

Question 11

What is the expected product when an ether is heated with concentrated hydriodic acid ($$HI$$)?

Accepted Answer

Cleavage of the ether to form two alkyl iodides and water.

Question 12

Which of the following is NOT a property of ethers?

Accepted Answer

Ethers can hydrogen bond with other ether molecules.

Question 13

In the acid-catalyzed opening of an epoxide in alcohol solution, what is the stereochemistry of the product?

Accepted Answer

Anti addition, resulting in an alkoxy alcohol.

Question 14

Which of the following statements about cyclic ethers (heterocycles) is correct?

Accepted Answer

Oxygen is part of the ring structure in cyclic ethers.

Question 15

What is the main reason for the thermodynamic favorability of epoxide ring opening?

Accepted Answer

Release of ring strain, which is about $$25$$ kcal/mol for epoxides.

Question 16

Which of the following is a correct statement about the reaction of epoxides with Grignard reagents?

Accepted Answer

Grignard reagents open the epoxide ring by attacking the less hindered carbon atom.

Question 17

Which of the following is a correct IUPAC name for the compound $$CH_3CH_2SCH_2CH_3$$?

Accepted Answer

Diethyl sulfide

Question 18

Which of the following is true regarding the solvation of ions in ether solvents?

Accepted Answer

Ethers solvate small cations well due to lone pairs on oxygen, but do not solvate small anions effectively.

Question 19

Which of the following is a correct statement about the use of silyl ethers in protecting alcohols during Grignard reactions?

Accepted Answer

Protecting the alcohol as a silyl ether prevents it from reacting with the Grignard reagent.

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

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