Question 1

Which reagent is commonly used to oxidize a primary alcohol to an aldehyde without further oxidation to a carboxylic acid?

Accepted Answer

PCC (Pyridinium chlorochromate)

Question 2

What is the product when a secondary alcohol is oxidized using PCC?

Accepted Answer

Ketone

Question 3

Which of the following best describes the reactivity of ketones and aldehydes toward nucleophilic addition?

Accepted Answer

Aldehydes are more reactive than ketones due to less steric hindrance and greater electrophilicity.

Question 4

In the reaction of an aldehyde with a Grignard reagent ($$R-MgBr$$), what is the major product after aqueous workup?

Accepted Answer

Secondary alcohol

Question 5

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

Accepted Answer

LiAlH\_4

Question 6

During the nucleophilic addition of a strong nucleophile (such as $$R-MgBr) to a $$carbonyl compound, what is the first step of the mechanism?

Accepted Answer

Attack of the nucleophile on the carbonyl carbon

Question 7

Which of the following is a correct statement about the reaction of ketones with weak nucleophiles under acidic conditions?

Accepted Answer

The carbonyl oxygen is protonated, increasing electrophilicity before nucleophilic attack.

Question 8

What is the product when benzaldehyde reacts with $$PhMgBr ($$phenylmagnesium bromide) followed by aqueous workup?

Accepted Answer

1,2-diphenylethanol

Question 9

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

Accepted Answer

Aldehydes have less steric hindrance and a more electrophilic carbonyl carbon.

Question 10

Which reagent is used in the ozonolysis of alkenes to produce ketones and/or aldehydes?

Accepted Answer

O\_3 followed by Zn/H\_2O

Question 11

What is the product when cyclohexanone is treated with LiAlH\_4 followed by water?

Accepted Answer

Cyclohexanol

Question 12

Which of the following is a correct statement about the Friedel–Crafts acylation reaction?

Accepted Answer

It introduces an acyl group onto an aromatic ring using $$RCOCl$$ and $$AlCl_3.$$

Question 13

Which of the following is a strong nucleophile commonly used in the addition to carbonyl compounds?

Accepted Answer

$$R-MgBr ($$Grignard reagent)

Question 14

What is the major product when acetone reacts with methylmagnesium bromide ($$CH_3MgBr) $$followed by water?

Accepted Answer

tert-butanol

Question 15

Which of the following best describes the role of $$AlCl_3 in $$the Friedel–Crafts acylation?

Accepted Answer

It acts as a Lewis acid to activate the acyl chloride.

Question 16

Which of the following is the correct mechanism for the reduction of an aldehyde by NaBH\_4?

Accepted Answer

Hydride transfer to the carbonyl carbon followed by protonation of the oxygen

Question 17

Which of the following statements is true regarding the use of Grignard reagents in organic synthesis?

Accepted Answer

Grignard reagents add to carbonyl compounds to form alcohols after aqueous workup.

Question 18

What is the product when benzaldehyde is treated with LiAlH\_4 followed by water?

Accepted Answer

Benzyl alcohol

Question 19

Which of the following is a correct statement about the reaction of ketones with strong nucleophiles?

Accepted Answer

The reaction proceeds via nucleophilic addition to the carbonyl carbon.

Ketones and Aldehydes: Structure, Synthesis, and Reactivity

Study Guide - Practice Questions