Question 1

What is the major product when anisole (methoxybenzene) is treated with $$SO_3$$ and $$H_2SO_4 as $$shown below?

$$\ce{C6H5OCH3} + SO_3$/H_2SO_4 \rightarrow$$ ?

Accepted Answer

para-methoxybenzenesulfonic acid

$$\ce{p-CH3OC6H4SO3H}$$

Question 2

When benzoic acid is treated with $$Br_2$$ and $$FeBr_3$$, what is the major product?

$$\ce{C6H5CO2H} + Br_2$/$$FeBr_3$$ \rightarrow$$ ?

Accepted Answer

meta-bromobenzoic acid

$$\ce{m-BrC6H4CO2H}$$

Question 3

What is the major product when the following compound is treated with $$Br_2$$ and $$FeBr_3$$?

(Compound: phenoxyethylbenzene)

$$\ce{PhOCH2C6H5} + Br_2$/$$FeBr_3$$ \rightarrow$$ ?

Accepted Answer

Bromination occurs at the para position to the ethoxy group on the right ring.

Question 4

When phenoxyethylbenzene is treated with $$CH_3CH_2Cl$$ and $$AlCl_3$$, what is the major product?

$$\ce{PhOCH2C6H5} + CH_3CH_2Cl/$$AlCl_3$$ \rightarrow$$ ?

Accepted Answer

Ethyl group attaches to the para position of the right benzene ring (relative to the ethoxy group).

Question 5

What is the major product when 4-ethyl-3-propylacetophenone is treated with $$HNO_3$$ and $$H_2SO_4$$?

$$\ce{C2H5C6H3(COCH3)C3H7} + $$HNO_3$$/H_2SO_4 \rightarrow$$ ?

Accepted Answer

Nitration occurs at the meta position to the acetyl group.

Question 6

Which of the following best describes the directing effects of the ethoxy group ($$-OCH_2CH_3) in $$the compound below?

$$\ce{C2H5C6H4OCH2CH3}$$

Accepted Answer

It is an ortho/para-directing activator.

Question 7

In the biphenyl ether shown below, which ring is more activated toward electrophilic aromatic substitution and why?

$$\ce{C6H5-C6H4OCH3}$$

Accepted Answer

The ring with the $$-$$OCH_3$$ group is more activated due to resonance donation.

Question 8

Which of the following is the correct order of reactivity toward electrophilic aromatic substitution for the following substituents on benzene?

$$-NO_2$, $$-$$OCH_3$$, $$-CO_2H$$, $$-CH_3$

Accepted Answer

$$-$$OCH_3$$ \u003e -CH_3$ \u003e -CO_2H \u003e -NO_2$

Question 9

Which of the following best explains why $$-$$OCH_3$$ is a stronger activator than $$-$$OCOCH_3 on a $$benzene ring?

Accepted Answer

$$-$$OCH_3$$ can donate electron density by resonance and induction, while $$-$$OCOCH_3 is $$less effective due to resonance delocalization into the carbonyl.

Question 10

Which of the following compounds will react most rapidly with $$CH_3CH_2Cl$$ and $$AlCl_3 in a $$Friedel-Crafts alkylation?

Accepted Answer

anisole

Question 11

In electrophilic aromatic substitution, why is the hydroxyl group ($$-OH) an $$ortho/para director?

Accepted Answer

It donates electron density to the ring by resonance and stabilizes the ortho and para sigma complexes.

Question 12

Which of the following species is the actual electrophile in the nitration of benzene?

Accepted Answer

$$NO_2$$^+$$

Question 13

Which of the following compounds will NOT undergo Friedel-Crafts acylation?

Accepted Answer

benzophenone

Question 14

In electrophilic aromatic substitution, a cyano group ($$-CN) on $$the aromatic ring is:

Accepted Answer

a deactivator and a meta-director

Question 15

Which of the following best describes the effect of a phenyl substituent on an aromatic ring in electrophilic aromatic substitution?

Accepted Answer

an activator and an ortho/para-director

Question 16

Which of the following is the correct sequence of reagents to convert benzene into m-bromoethylbenzene?

Accepted Answer

1. $$HNO_3$$, $$H_2SO_4$$; 2. $$Br_2$$, $$FeBr_3$$; 3. $$Sn$$, $$HCl$$; 4. $$CH_3CH_2Cl$$, $$AlCl_3$$

Question 17

Which of the following best explains why $$-$$NHCOCH_3$$ is a deactivator and an ortho/para director?

Accepted Answer

It withdraws electrons by induction but can donate by resonance to ortho/para positions.

Organic Chemistry: Electrophilic Aromatic Substitution – Practice Problems with Step-by-Step Guidance

Guida di studio - Domande di pratica

Study guide - Flashcard