Radical Substitution

Question 1

Radical

Answer 1

A species with an unpaired electron => aren’t positive or negative

Question 2

Conditions for alkenes to react w/ halogens

Answer 2

• Alkenes react w/ x in presence of ultraviolet (UV) light to form halogenated organic compounds such as haloalkanes

Question 3

Stages of Halogenation of Alkanes

Answer 3

(1) Homolytic fission of halogen molecules forming radicals
(2) A H atom in the alkane is substituted by a halogen atom
* in some cases, if reaction conditions are maintained, the reaction can continue until all Hs are replaced with halogens

Question 4

Mechanism for Bromination of Alkanes

Answer 4

Chemical reaction can be shown in a series of steps showing where electrons are transferred

=> 3 stages - all occurs simultaneously

Question 5

Initiation

Answer 5

• Reaction is started when the covalent bond in the halogen is broken by homolytic fission

Question 6

Propagation

Answer 6

Sets up chain reaction to make more radicals

Question 7

Termination

Answer 7

When 2 radicals join to end chain reaction

Question 8

Further substitution (limitation)

Answer 8

Reaction can continue until all H atoms have been subbed - can form undesired products

Question 9

Substitution at diff points in carbon chain

Answer 9

On larger chains substitution in different points - creating undesired products