Chloroalkanes and CFCs

Question 1

What is a free radical

Answer 1

Particle with an unpaired electron

Question 2

How do free radicals form

Answer 2

When a covalent bond splits equally, giving one electron to each atom

Question 3

Steps of a free radical substitution reaction

Answer 3

Initiation
Propagation
Termination

Question 4

First propagation step always involves

Answer 4

Chlorine free radical

Question 5

Second propagation step involves

Answer 5

Cl2

Question 6

Define chlorofluorocarbons

Answer 6

Halogenoalkane molecules where all of the hydrogen atoms have been replaced by chlorine and fluorine atoms

Question 7

What does UV radiation cause

Answer 7

Sunburn

Skin cancer

Question 8

Give an example of an ozone intermediate

Answer 8

ClO•

Question 9

What are the steps for the synthesis of cholormethane

CH4 + Cl2 –> CH3Cl + HCl in the presence of UV light

Answer 9

Initiation
Cl2 –> Cl• + Cl•
UV light required

Propagation 1
Cl• + CH4 –> •CH3 + HCl

Propagation 2
•CH3 + Cl2 –> CH3Cl + Cl•

Termination
Cl• + •CH3 –> CH3Cl

Question 10

What is photodissociation

Answer 10

The breaking of Cl-Cl bonds with energy provided by sunlight