CFC's, NOx and the Ozone Layer

Question 1

How do you answer Ozone depletion questions?

Answer 1

• natural equilibrium of UV light
• harmful effect of UV light
• initial equation
• propagation
• overall

Question 2

What is ozone depletion by CFC’s?

Answer 2

O3  O2 + O
UV light: skin cancer
Initiation: 
- CF2Cl2 -- UV --> *CF2Cl + Cl*
Propagation: 
- Cl* + O3 --> ClO* + O2
- ClO* + O --> O2 + Cl*
Overall:
- O3 + O - Cl catalyst -> 2O2

Question 3

What is ozone depletion by Nitrogen monoxides?

Answer 3

O3  O2 + O
UV light: skin cancer
Sources: lighting, jet aircraft engines
Initiation: 
- N2 + O2 -- UV --> 2*NO
Propagation: 
- *NO + O3 --> *NO2 + O2
- *NO2 + O --> O2 + *NO
Overall:
- O3 + O - Ni catalyst -> 2O2

Question 4

Which bond breaks first out of the following?
C-Cl
C-F
C-H

Answer 4

C-H - lower the bond strength, decomposes before reaching the outer atmosphere

Question 5

What are two sources of nitrogen oxides in the stratosphere?

Answer 5

Lightning, jet aircraft engine