Formation of Industrial Smog
Step Chemical Reaction
- Carbon in coal or oil is burned in
oxygen gas to produce carbon dioxide
and carbon monoxide gas.
C + O 2 → CO 2
C + O 2 → CO
- Unburned carbon ends up as soot or
particulate matter (PM). C
- Sulfur in oil and coal reacts with
oxygen gas to produce sulfur dioxide.
S + O 2 → SO 2
- Sulfur dioxide reacts with oxygen gas
to produce sulfur trioxide.
SO 2 + O 2 → SO 3
- Sulfur trioxide reacts with water vapor
in the air to form sulfuric acid.
SO 3 + H 2 O → H 2 SO 4
- Sulfuric acid reacts with atmospheric
ammonia to form brown, solid
ammonium sulfate.
H 2 SO 4 + NH 3 →
(NH 4 ) 2 SO 4
PHOTOCHEMICAL SMOG
■ 6 A.M.– 9 A.M.
As people drive to work, concentrations of nitrogen oxides and VOCs
increase:
N 2 + O 2 → 2NO
NO + VOCs → NO 2
uv
NO 2 → NO + O
■ 9 A.M.– 11 A.M.
As traffic begins to decrease, nitrogen oxides and VOCs begin to react,
forming nitrogen dioxide:
