Question 1

Which of the following statements best explains why free radical compounds are highly reactive?

Accepted Answer

They do not follow the octet rule, resulting in an unpaired electron that makes them unstable.

Question 2

In the homolytic cleavage of a peroxide, what are the products formed from the following reaction? $$ \mathrm{R-O-O-R} \rightarrow $$

Accepted Answer

$$ \mathrm{R-O\cdot} + \mathrm{O-R\cdot} $$

Question 3

Which type of carbon radical is the most stable?

Accepted Answer

Tertiary radical

Question 4

Why are allylic radicals more stable than vinylic radicals?

Accepted Answer

Allylic radicals are resonance stabilized, allowing delocalization of the unpaired electron.

Question 5

During radical halogenation of butane with chlorine, which product is favored and why?

Accepted Answer

2-Chlorobutane, because secondary radicals are more stable than primary radicals.

Question 6

Which step in a radical chain reaction mechanism is responsible for generating the initial radical species?

Accepted Answer

Initiation

Question 7

What is the role of NBS (N-bromosuccinimide) in allylic bromination?

Accepted Answer

It selectively brominates the allylic position in the presence of ultraviolet light.

Question 8

Which of the following best describes the propagation step in a radical halogenation reaction?

Accepted Answer

A radical reacts with a stable molecule to form a new radical and a product.

Question 9

In the radical halogenation of methane, what is the overall reaction equation?

Accepted Answer

$$ \mathrm{CH_4$ + Cl_2$ \rightarrow CH_3Cl + HCl} $$

Question 10

Which of the following statements about polymerization by radical mechanisms is correct?

Accepted Answer

Radical polymerization involves the addition of monomers to a growing chain initiated by a radical.

Question 11

Which naturally occurring polymer is formed from glucose monomers?

Accepted Answer

Cellulose

Question 12

What is the effect of resonance stabilization on the reactivity of allylic radicals?

Accepted Answer

It decreases their reactivity by delocalizing the unpaired electron.

Question 13

Which of the following is NOT a step in the radical chain reaction mechanism?

Accepted Answer

Condensation

Question 14

During the radical halogenation of methane, which species is responsible for abstracting a hydrogen atom from methane?

Accepted Answer

Cl$$ \cdot $$ radical

Question 15

Which of the following best explains why tertiary radicals form faster than primary radicals in halogenation reactions?

Accepted Answer

Tertiary radicals are more stabilized by hyperconjugation and inductive effects.

Question 16

What is the major product when cyclohexene is treated with NBS and ultraviolet light?

Accepted Answer

3-Bromocyclohexene

Question 17

Which of the following is a correct description of the termination step in a radical chain reaction?

Accepted Answer

Two radical species combine to form a stable molecule, ending the chain reaction.

Question 18

Which of the following is a synthetic polymer formed by radical polymerization of ethylene?

Accepted Answer

Polyethylene

Question 19

Which of the following statements about radical reactions is true?

Accepted Answer

Radical reactions are less common and less predictable than electron pair reactions.

Chapter 11: Radicals and Radical Reactions in Organic Chemistry

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