Organohalogen Compounds In The Environment

Question 1

What are some uses of organohalogen compounds?

Answer 1

• solvents
• pesticides
• flame retardants

Question 2

Why are organohalogen compounds an issue?

Answer 2

They are not broken down naturally by the environment

Question 3

Describe what is happening in the ozone layer.

Answer 3

1. UV continuously causes ozone to be broken down and formed
2. Initially UV breaks oxygen molecules down into oxygen radicals
3. The rate of oxygen formation is equal to the rate of oxygen hydrolysis

Question 4

What happens when CFCs reach the stratosphere?

Answer 4

They begin to break down forming chlorine radicals which catalyse the breakdown of the ozone layer.

Question 5

How so CFCs deplete the ozone layer?

Answer 5

1. Photodissociation of the CFCs form chlorine radicals
2. Cl. + O3 —> ClO. + O2
   ClO. + O3 —> 2O2 + Cl.
3. Chlorine radical is regenerated so the cycle is repeated over and over again