What is the first step in photochemical smog formation?
Nitrogen dioxide ($NO_2$) from various sources is released into the atmosphere.
What happens to $NO_2$ in sunlight?
Sunlight breaks $NO_2$ into NO + O.
How is tropospheric ozone formed in smog?
O + $O_2$ (with sunlight) → $O_3$.
What happens at night in photochemical smog formation?
$O_3$ + NO → $NO_2$ + $O_2$.
What role do VOCs play in photochemical smog formation?
VOCs react with NO, forming photochemical oxidants that disrupt the breakdown of ozone.
What pollutants are released in industrial smog formation?
$SO_2$, particulate matter, and $NO_x$ are released from burning fossil fuels and industrial processes.
What do the pollutants from industrial smog react to form?
Sulfuric acid, particulate matter, and nitrogen dioxide.
Describe the formation of photochemical oxidants.
VOCs react with NO to form photochemical oxidants.
How does ozone contribute to photochemical smog?
Ozone combines with photochemical oxidants to form photochemical smog.
Summarize the process of industrial smog formation.
Pollutants from burning fossil fuels react to form sulfuric acid, particulate matter, and nitrogen dioxide, creating a thick haze.
What is gray smog?
Industrial smog, mainly from sulfur dioxide.
What is sulfurous smog?
Another name for gray smog.
What is brown smog?
Photochemical smog, with nitrogen compounds giving it a brownish color.
What is photochemical smog?
Smog formed by sunlight reacting with pollutants.
What are VOCs?
Volatile Organic Compounds, released from vehicles, industrial processes, and even trees.
What is tropospheric ozone?
Ozone in the lower atmosphere; a key component of photochemical smog.
Define industrial smog.
Smog from industrial emissions, especially from burning coal.
Define photochemical smog.
Smog formed when sunlight reacts with pollutants.
What is $SO_2$?
Sulfur dioxide, the main pollutant in industrial smog.
What are $NO_x$?
Nitrogen oxides, a main pollutant in photochemical smog.
What are the steps of photochemical smog formation?
1. $NO_2$ breaks down into NO + O (sunlight). 2. O + $O_2$ → $O_3$ (sunlight). 3. VOCs react with NO, forming photochemical oxidants. 4. $O_3$ + oxidants = smog.
Describe the nighttime reaction in photochemical smog formation.
$O_3$ + NO → $NO_2$ + $O_2$
What are the steps of industrial smog formation?
1. $SO_2$, particulate matter, and $NO_x$ are released. 2. Pollutants react to form sulfuric acid, particulate matter, and nitrogen dioxide. 3. This mix creates the thick haze.
Explain how nitrogen dioxide contributes to ozone formation.
Sunlight breaks $NO_2$ into NO and O; the free oxygen (O) combines with atmospheric oxygen ($O_2$) to form ozone ($O_3$).
How do VOCs disrupt the breakdown of ozone?
VOCs react with NO, forming photochemical oxidants that prevent NO from reacting with ozone.
What happens to ozone at night in areas with high NO concentrations?
Ozone reacts with NO to form $NO_2$ and $O_2$, reducing ozone levels.
