Question 1

Which of the following statements best explains why aldehydes are generally more reactive toward nucleophilic addition than ketones?

Accepted Answer

Aldehydes have a more positive carbonyl carbon due to only one electron-donating group.

Question 2

What is the IUPAC name for the following compound: $$\mathrm{ClCH_2CH_2C(CH_3$)_2CH=O}$$?

Accepted Answer

4-Chloro-2,2-dimethylpentanal

Question 3

Which reagent is most suitable for oxidizing a primary alcohol to an aldehyde without further oxidation to a carboxylic acid?

Accepted Answer

PCC (Pyridinium chlorochromate)

Question 4

Which of the following best describes the product of the reaction between a ketone and a primary amine under acidic conditions?

Accepted Answer

An imine

Question 5

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

Accepted Answer

PCC or H$$_2$$CrO$$_4$$

Question 6

Which of the following is a correct statement about the IR spectrum of an aldehyde?

Accepted Answer

It shows a strong C=O stretch near 1720 cm$$^{-1}$$ and a weak C-H stretch near 2720 cm$$^{-1}.$$

Question 7

Which of the following reactions will produce a cyanohydrin?

Accepted Answer

Addition of HCN to a ketone

Question 8

What is the oxidation state of the carbon in methanol ($$\mathrm{CH_3OH}$$)?

Accepted Answer

$$-2$$

Question 9

Which of the following best describes the mechanism of nucleophilic addition to a carbonyl group?

Accepted Answer

The nucleophile attacks the electrophilic carbonyl carbon, forming a tetrahedral intermediate.

Question 10

Which test is commonly used to distinguish between aldehydes and ketones?

Accepted Answer

Tollens' test (silver mirror test)

Question 11

A Grignard reagent reacts with a ketone followed by hydrolysis. What is the major product?

Accepted Answer

A tertiary alcohol

Question 12

Which of the following is a correct order of increasing oxidation state for carbon in the following compounds: methane, methanol, formaldehyde, formic acid?

Accepted Answer

Methane \u003c Methanol \u003c Formaldehyde \u003c Formic acid

Question 13

Which of the following statements about the formation of imines from aldehydes or ketones and primary amines is correct?

Accepted Answer

The reaction is reversible and can be driven to completion by removing water.

Question 14

Which of the following best describes the product formed when a secondary amine reacts with a ketone under acidic conditions?

Accepted Answer

An enamine

Question 15

Which of the following is a correct statement about the $$^{13}C $$NMR spectrum of a ketone?

Accepted Answer

The carbonyl carbon appears in the $$\delta 180$$–220 ppm region.

Question 16

Which of the following is a synthetic application of cyanohydrin formation?

Accepted Answer

Conversion of a carbonyl compound to an $$\alpha-$$hydroxy acid

Question 17

Which of the following best describes the effect of conjugation on the IR absorption frequency of the C=O stretch in aldehydes and ketones?

Accepted Answer

Conjugation lowers the C=O absorption frequency by about 40 cm$$^{-1}.$$

Question 18

Which of the following is the correct product when a Grignard reagent reacts with formaldehyde followed by hydrolysis?

Accepted Answer

A primary alcohol

Question 19

Which of the following is a distinguishing $$^1H $$NMR feature of an aldehyde?

Accepted Answer

A singlet in the $$\delta 9$$–12 ppm region

Aldehydes and Ketones: Synthesis, Properties, and Nucleophilic Addition Reactions

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