Question 1

Which of the following statements best explains why the C=O bond in a ketone is shorter and stronger than the C=C bond in an alkene?

Accepted Answer

The C=O bond involves a more electronegative atom (oxygen), resulting in greater s-character and stronger overlap.

Question 2

Which compound would have the highest boiling point among the following: butane, methoxyethane, propanal, acetone, or propan-1-ol? Explain your reasoning.

Accepted Answer

Propan-1-ol, because it can hydrogen bond with itself.

Question 3

Which IR absorption is most characteristic of a simple aldehyde?

Accepted Answer

$$1725\ \mathrm{cm}^{-1}$$ and two C-H stretches at 2710 and 2810\ \mathrm{cm}^{-1}$

Question 4

Which of the following best describes the product(s) of ozonolysis of 2,3-dimethyl-2-butene?

Accepted Answer

Two molecules of acetone

Question 5

A compound gives a strong IR absorption at $$1710\ \mathrm{cm}^{-1}$$ and a singlet at $$\delta 2.1 in $$its $$^1H $$NMR spectrum. Which functional group is most likely present?

Accepted Answer

Methyl ketone

Question 6

Which reagent would 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 why aldehydes are generally more reactive toward nucleophilic addition than ketones?

Accepted Answer

Aldehydes are less sterically hindered and their carbonyl carbon is more electrophilic due to only one electron-donating group.

Question 8

Which of the following reactions would be used to synthesize a ketone from a carboxylic acid?

Accepted Answer

Reaction with a lithium dialkylcuprate (Gilman reagent) after conversion to an acid chloride

Question 9

Which of the following statements about the McLafferty rearrangement in mass spectrometry is correct?

Accepted Answer

It involves the transfer of a hydrogen from the $$\gamma-$$carbon to the carbonyl oxygen, resulting in the formation of an alkene and an enol.

Question 10

Which of the following best describes the product of the reaction of acetone with ethylmagnesium bromide followed by aqueous acid?

Accepted Answer

2-methyl-2-butanol

Question 11

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

$$\mathrm{CH_3CH(OH)CH_2COCH_2CH_3}$$

Accepted Answer

5-hydroxyhexan-3-one

Question 12

Which of the following statements about the Wittig reaction is correct?

Accepted Answer

It converts a carbonyl group into a new C=C double bond using a phosphorus ylide.

Question 13

Which of the following reagents can reduce both ketones and carboxylic acids to alcohols?

Accepted Answer

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

Question 14

Which of the following best describes the role of acetals in organic synthesis?

Accepted Answer

They act as protecting groups for carbonyl compounds.

Question 15

Which of the following is the correct order of priority for naming organic compounds according to IUPAC rules (from highest to lowest)?

Accepted Answer

Acids \u003e esters \u003e aldehydes \u003e ketones \u003e alcohols \u003e amines \u003e alkenes/alkynes \u003e alkanes \u003e ethers \u003e halides

Question 16

Which of the following best describes the product of the hydration of 1-butyne using HgSO$$_4$$ and H$$_2SO$_4$$?

Accepted Answer

Butan-2-one (methyl ethyl ketone)

Question 17

Which of the following is a correct description of the Tollens test?

Accepted Answer

It is a chemical test used to distinguish aldehydes from ketones by the formation of a silver mirror.

Question 18

Which of the following best describes the mechanism of cyanohydrin formation from a ketone?

Accepted Answer

Base-catalyzed nucleophilic addition of cyanide ion to the carbonyl carbon, followed by protonation.

Ketones and Aldehydes: Structure, Properties, Nomenclature, and Reactions

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