1.5 - Photochemical Smog

Question 1

What is photochemical smog?

Answer 1

• A brown haze which is a mixture of air pollutants
• ## An irritant to the human respiratory system and eyes

Question 2

What are free radicals?

Answer 2

an unchanged molecule

Question 3

What are the main cause for photochemical smog?

Answer 3

motor vehicles and their exhaust fumes

Question 4

What are the primary pollutants?

Answer 4

Any pollutant directly emitted into the air. 
Eg: 
- Carbon Monoxide (CO) 
- Sulphur Dioxide (SO2) 
- Carbon Dioxide (CO2) 
- Nitric oxide (NO) 
- Unburnt hydrocarbons

Question 5

What are secondary pollutants

Answer 5

These do not have direct emission source because of the photochemical reactions of primary pollutants 
Eg. 
- Ozone (O3) 
- Nitrogen dioxide (NO2)
- Peroxyacety nitrate (PAN)
- Sulphurous Acide (H2SO3)
- Sulphuric Acid (H2SO4)
- Aldehydes