Question 1

Which of the following substituents on a benzene ring will most likely increase the rate of electrophilic aromatic substitution and direct the incoming group to the ortho and para positions?

Accepted Answer

OCH$$_3$$

Question 2

A benzene ring substituted with a nitro group (NO$$_2) $$undergoes bromination. Where will the major product form and why?

Accepted Answer

Meta position because NO$$_2 is an $$electron-withdrawing group and meta director

Question 3

Which of the following statements about NMR spectroscopy is TRUE?

Accepted Answer

Electronegative atoms attached to protons cause deshielding, moving the signal downfield

Question 4

A compound with the formula C$$_7H$_8O $$has an HDI (hydrogen deficiency index) of 4. What does this indicate about its structure?

Accepted Answer

It contains a combination of rings and double bonds totaling four degrees of unsaturation

Question 5

Which reagent would selectively reduce an ester to an aldehyde without further reduction to an alcohol?

Accepted Answer

DIBAL-H at $$-78\ ^\circC $$followed by H$$_2O $$workup

Question 6

In the Friedel-Crafts acylation of benzene, which of the following is required to generate the acylium ion?

Accepted Answer

AlCl$$_3$$

Question 7

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

Accepted Answer

Aldehydes are less sterically hindered and have fewer electron-donating groups, making the carbonyl more electrophilic

Question 8

A molecule shows three NMR signals with integration ratios of 3:2:1. Which of the following is the most likely structure?

Accepted Answer

CH$$_3CH$_2$$CHO

Question 9

Which of the following is a correct application of the N+1 rule in $$^1H $$NMR splitting patterns?

Accepted Answer

A proton with two equivalent neighboring protons will appear as a triplet

Question 10

Which of the following reactions is used to convert an aldehyde to a carboxylic acid?

Accepted Answer

KMnO$$_4$$

Question 11

Which of the following is NOT a suitable protecting group for a carbonyl during organometallic addition?

Accepted Answer

Thioacetal

Question 12

What is the product of the reaction between benzaldehyde and Ph$$_3P=CH$_2 ($$Wittig reagent)?

Accepted Answer

Styrene ($$C_6H_5CH=CH_2$)

Question 13

Which of the following statements about the Horner-Wadsworth-Emmons reaction is correct?

Accepted Answer

It uses a phosphonate ester and favors E-alkene formation

Question 14

Which of the following nucleophiles will react with an aldehyde to form an imine?

Accepted Answer

NH$$_3$$

Question 15

Which reagent is used in the Wolff-Kishner reduction to remove a carbonyl group from a ketone?

Accepted Answer

NH$$_2NH$_2$$ and KOH

Question 16

Which of the following statements about acetal formation is TRUE?

Accepted Answer

Acetal formation requires acidic conditions

Question 17

Which of the following is the correct mechanism for the reduction of a nitrile to an aldehyde using DIBAL-H?

Accepted Answer

DIBAL-H adds to the nitrile, forming an imine intermediate, which is hydrolyzed to an aldehyde

Question 18

Which of the following is a reason why halides are ortho/para directors but deactivating in electrophilic aromatic substitution?

Accepted Answer

Halides donate electrons by resonance but withdraw electrons by induction

Question 19

Which of the following is NOT a product of the reaction between a ketone and hydrazine (NH$$_2NH$_2$$)?

Accepted Answer

Imine

Aromatic Substitution, NMR Spectroscopy, and Aldehyde/Ketone Chemistry

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