Question 1

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

Accepted Answer

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

Question 2

What is the product when a Grignard reagent, $$CH_3MgBr$$, reacts with formaldehyde ($$H_2C=O) $$followed by aqueous workup?

Accepted Answer

A primary alcohol, $$CH_3CH_2OH$$

Question 3

Which of the following best describes the hybridization and geometry of the carbonyl carbon in aldehydes and ketones?

Accepted Answer

sp$$^2$$ hybridized, trigonal planar geometry

Question 4

A chemist wants to convert a carboxylic acid to a primary alcohol. Which reagent is most appropriate for this transformation?

Accepted Answer

Lithium aluminum hydride ($$LiAlH_4)$$

Question 5

Which of the following is a correct statement about the reaction of organometallic reagents (such as Grignard or organolithium) with epoxides?

Accepted Answer

The nucleophile attacks the less hindered carbon of the epoxide, opening the ring.

Question 6

Which of the following best explains why organometallic reagents must be prepared and used in aprotic solvents such as diethyl ether?

Accepted Answer

They are highly basic and will react rapidly with protic solvents, destroying the reagent.

Question 7

A chemist wants to synthesize 2-phenyl-2-propanol from acetone and a suitable organometallic reagent. Which reagent should be used?

Accepted Answer

Phenylmagnesium bromide ($$C_6H_5MgBr)$$

Question 8

Which of the following is the correct product of the reaction between a Gilman reagent ($$R_2CuLi) $$and an acid chloride ($$R'COCl$$)?

Accepted Answer

A ketone, $$R'COR$$

Question 9

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

Accepted Answer

It converts a carbonyl group into an alkene using a phosphonium ylide.

Question 10

Which of the following is the best method to protect a carbonyl group during a reaction with a strong nucleophile?

Accepted Answer

Convert it to an acetal using a diol and acid catalyst.

Question 11

Which of the following carbonyl compounds is most reactive toward nucleophilic addition?

Accepted Answer

Formaldehyde ($$H_2C=O)$$

Question 12

A student attempts to react a Grignard reagent with a carboxylic acid. What is the most likely outcome?

Accepted Answer

The Grignard reagent will be protonated and destroyed, producing an alkane.

Question 13

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 14

Which reagent is most selective for reducing only aldehydes and ketones, but not carboxylic acids or esters?

Accepted Answer

Sodium borohydride ($$NaBH_4)$$

Question 15

Which of the following is a correct statement about the reactivity of carbonyl compounds?

Accepted Answer

The more substituted the carbonyl carbon, the less reactive it is toward nucleophilic attack due to steric hindrance.

Question 16

A chemist wants to add two carbons to a carbonyl compound and convert it into an alcohol. Which sequence of reagents would achieve this?

Accepted Answer

React with ethylmagnesium bromide ($$C_2H_5MgBr) $$followed by aqueous workup.

Question 17

Which of the following best describes the product of the reaction between a Grignard reagent and carbon dioxide ($$CO_2) $$followed by acid workup?

Accepted Answer

A carboxylic acid

Question 18

Which of the following is a correct statement about the use of protecting groups in carbonyl chemistry?

Accepted Answer

Protecting groups such as acetals prevent unwanted reactions at the carbonyl during synthesis.

Question 19

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

$$\mathrm{CH_3CH_2COCH_2CH_3}$$

Accepted Answer

2-Pentanone

Question 20

Which of the following best explains why the carbonyl carbon is electrophilic?

Accepted Answer

The oxygen atom is more electronegative, pulling electron density away from the carbon.

Organometallics and Reactions of Aldehydes & Ketones: Structure, Reactivity, and Nomenclature

Study Guide - Practice Questions