Question 1

Which of the following best describes the aromaticity of benzene?

Accepted Answer

Benzene is aromatic because it is planar, cyclic, fully conjugated, and follows Hückel's rule with $$6$$ π electrons.

Question 2

Which of the following is the correct major resonance form for the acetate ion ($$CH_3COO^-$$)?

Accepted Answer

The negative charge is delocalized equally between the two oxygens.

Question 3

Which of the following compounds is aromatic?

Accepted Answer

Pyrrole

Question 4

Which product is favored under kinetic control in a Diels-Alder reaction?

Accepted Answer

The product formed fastest, typically the endo product.

Question 5

In the Diels-Alder reaction between cyclopentadiene and maleic anhydride, which product is most likely formed and why?

Accepted Answer

The endo product due to secondary orbital interactions.

Question 6

Which of the following best describes the difference between kinetic and thermodynamic products in an electrophilic addition to a conjugated diene?

Accepted Answer

Kinetic products form faster and are favored at low temperatures; thermodynamic products are more stable and favored at high temperatures.

Question 7

Which of the following is the best representation of the hybrid structure of benzene?

Accepted Answer

A hexagon with a circle inside, indicating delocalized π electrons.

Question 8

Which of the following reagents would you use to convert a benzene ring to ortho-dichlorobenzene?

Accepted Answer

$$Cl_2$$, $$FeCl_3 ($$catalyst)

Question 9

Which of the following is the correct order of stability for the following carbocations: benzyl, allyl, methyl?

Accepted Answer

Benzyl \u003e Allyl \u003e Methyl

Question 10

Which of the following is the correct mechanism for the bromination of benzene?

Accepted Answer

Benzene reacts with $$Br_2 in $$the presence of $$FeBr_3$$, forming a sigma complex, followed by deprotonation.

Question 11

Which of the following best describes the product of the reaction: $$1,3-$$butadiene + $$HBr at$$ $$-80^\circ C$$?

Accepted Answer

The $$1,2-$$addition product is favored (kinetic control).

Question 12

Which of the following is the correct sequence of reagents to synthesize meta-nitroaniline from benzene?

Accepted Answer

Nitrate first, then reduce to aniline: $$HNO_3/H_2SO_4$, then H_2$/Pd$$

Question 13

Which of the following statements about the Diels-Alder reaction is correct?

Accepted Answer

It is a concerted [4+2] cycloaddition reaction.

Question 14

Which of the following is the best description of the endo rule in Diels-Alder reactions?

Accepted Answer

The endo product is favored due to secondary orbital interactions between the diene and the dienophile.

Question 15

Which of the following is the correct resonance structure for the nitro group ($$NO_2) $$attached to a benzene ring?

Accepted Answer

One oxygen has a negative charge, nitrogen has a positive charge, and the other oxygen is neutral.

Question 16

Which of the following best explains why ortho/para directors activate the benzene ring toward electrophilic aromatic substitution?

Accepted Answer

They donate electron density to the ring via resonance or induction.

Question 17

Which of the following is the correct product for the reaction: benzene + $$Br_2 ($$excess) + $$FeBr_3$$?

Accepted Answer

1,3,5-tribromobenzene

Question 18

Which of the following is the correct order of reactivity toward electrophilic aromatic substitution: toluene, benzene, nitrobenzene?

Accepted Answer

Toluene \u003e Benzene \u003e Nitrobenzene

Drawing Resonance Structures: Guidance for Organic Chemistry II

Study Guide - Practice Questions