Question 1

In Figure A, what is the major organic product formed when the starting compound is treated with 1. HOCH2CH2MgBr, THF; 2. H3O+, H2O?

Accepted Answer

A secondary alcohol formed by nucleophilic addition of the Grignard reagent to the carbonyl group.

Question 2

Refer to Figure E. Which reagent would best convert a primary alcohol to an aldehyde without further oxidation to a carboxylic acid?

Accepted Answer

PCC (Pyridinium chlorochromate)

Question 3

In Figure G, what is the role of H3O+ in the second step of the reaction sequence?

Accepted Answer

To protonate the alkoxide intermediate and yield the final alcohol product.

Question 4

Figure I shows a reaction with NaBH4 and then LiAlH4. Which statement best describes the difference in reactivity between these two reagents?

Accepted Answer

NaBH4 selectively reduces aldehydes and ketones, while LiAlH4 reduces esters, carboxylic acids, and amides.

Question 5

Using the pKa table on page 5, which of the following compounds is the strongest acid?

Accepted Answer

CH3COOH (acetic acid), pKa ≈ 5

Question 6

In Figure W, what is the product of the reaction of an alcohol with PCl3?

Accepted Answer

An alkyl chloride formed by substitution of the hydroxyl group.

Question 7

Figure Q shows a multi-step synthesis. What is the purpose of using NaOEt in the first step?

Accepted Answer

To generate an enolate ion for nucleophilic attack in the Claisen condensation.

Question 8

In Figure S, which compound would be the most nucleophilic in a typical SN2 reaction?

Accepted Answer

The primary amine (S-2)

Question 9

Refer to Figure O. Which product is formed when a ketone reacts with a Grignard reagent followed by aqueous workup?

Accepted Answer

A tertiary alcohol

Question 10

In Figure R, what is the function of PCC in the reaction sequence?

Accepted Answer

To oxidize a primary alcohol to an aldehyde

Question 11

Figure N shows resonance structures. Which statement best explains the stability of the carboxylate ion?

Accepted Answer

Delocalization of negative charge over two oxygen atoms increases stability.

Question 12

In Figure V, which compound is most likely to undergo nucleophilic addition with NaBH4?

Accepted Answer

The compound containing a carbonyl group (V-3)

Question 13

Using the organic periodic table, which element is most likely to act as a nucleophile in organic reactions?

Accepted Answer

Nitrogen (N)

Question 14

In Figure U, what is the role of LDA in the reaction sequence?

Accepted Answer

To generate an enolate ion by deprotonating the alpha hydrogen of a ketone.

Question 15

Figure L shows a reaction with NaOH, H2O, heat. What is the expected product of this reaction with an ester?

Accepted Answer

A carboxylate ion and an alcohol via saponification.

Question 16

In Figure X, which compound is most likely to undergo an SN1 reaction?

Accepted Answer

The tertiary alkyl halide (X-2)

Question 17

Refer to Figure Y. Which functional group is present in Y-2?

Accepted Answer

Ketone

Question 18

In Figure P, what is the product of the reaction of a ketone with HCN?

Accepted Answer

A cyanohydrin

Question 19

Using the pKa table, which hydrogen is most acidic: on a carboxylic acid, on an alcohol, or on an alkane?

Accepted Answer

On a carboxylic acid (pKa ≈ 5)

Organic Chemistry Reaction Mechanisms and Acid-Base Properties: Practice Exam Structure Sheet

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