ME1APHO8

1. What is the first step in the general mechanism for electrophilic aromatic substitution?

• A) Protonation of the aromatic ring

• B) Deprotonation of the aromatic ring

• C) Addition of the electrophile to the aromatic ring

• D) Loss of the electrophile from the aromatic ring

2. What is the driving force for losing a proton as the last step in electrophilic aromatic substitution?

• A) To neutralize the base that is present

• B) To make room for the electrophile

• C) To make the ring more reactive

• D) To rearomatize the ring system

3. What is the electrophile in aromatic nitration?

• A) NO+

• B) NO2+

• C) NO3+

• D) NO2H

4. What is the electrophile in aromatic sulfonation?

• A) H2SO3

• B) H2SO4

• C) SO3+

• D) HSO3+

5. Why is sulfuric acid used in aromatic nitration?

• A) To keep the reaction from getting too basic

• B) To form the active electrophile NO2+

• C) To protonate the aromatic ring

• D) To keep the reaction from getting too acidic

6. What is the electrophile in the Friedel-Crafts alkylation reaction with tert-butylchloride?

• A) the tert-butyl cation

• B) a complex of tert-butylchloride and aluminum chloride

• C) a proton

• D) aluminum chloride

7. Which of the following halides will not work as an electrophile in a Friedel-Crafts alkylation reaction?

• A) I

• B) II

• C) III

• D) IV

8. What are the two effects that have to be considered to determine the influence a substituent will have on electrophilic aromatic substitution?

• A) Steric and electronic

• B) Inductive and steric

• C) Inductive and resonance

• D) Resonance and electronic

9. Why is the nitro group a meta director?

• A) Because it is sterically very large.

• B) Because it adds electron density to the meta position, thus activating it.

• C) Because it stabilizes the intermediate cation.

• D) Because it removes more electron density from the ortho and para positions than the meta position, thus deactivating the meta position less.

10. What is a major problem with Friedel-Crafts alkylation?

• A) It requires high temperatures.

• B) The conditions are too acidic.

• C) The starting material is frequently over-alkylated.

• D) The products coordinate with the aluminum chloride.