Radical Subsitution

Question 1

What is a mechanism

Answer 1

How a reaction works

Question 2

What are the three step of radical substitution

Answer 2

• initiation
• propagation
• termination

Question 3

What occurs in initiation

Answer 3

• two radicals are formed
• the covalent band between the two halogen atoms is broken by homolytic fission

Question 4

What is the equation and conditions for the initation of chlorine

Answer 4

Cl - Cl = Cl* + Cl*
UV light

Question 5

What occurs in propagation

Answer 5

• occurs in two steps and is a chain reaction
• each step of propagation causes a radical and a non radical to be produced

Question 6

Give the first step of propagation (methane and chlorine)

Answer 6

CH4 + Cl= CH3 + HCL

Question 7

Give the second step of propagation (methane and chlorine)

Answer 7

CH3* + Cl2 = CH3CL + Cl*

Question 8

What occurs in termination

Answer 8

• Two radicals collide and form a non radical
• There are many combinations for this

Question 9

Give three examples of termination ( chlorine and methane)

Answer 9

Cl* + Cl* = Cl2
CH3* + CH3* = C2H6
CH3+ CH3 = CH3CL

Question 10

What are two limitations of radical substitution

Answer 10

• the halogen can add to the same molecule more than once
• the halogen can add to more than one position on the molecule form in many unwanted isomers