Chemistry of Tropospheric Pollution: Sulfur, CO, NOx, and Greenhouse Gases

What percentage of sulfur release is due to natural sources?

23% natural sources

What is the primary source of sulfur dioxide (SO2) pollution in the US?

Burning of coal and oil, which accounts for 80% of total SO2.

What does SO2 oxidize to in the atmosphere?

SO3, which reacts with moisture to form sulfuric acid.

What is the pH of acid rain?

pH of 4

What is the pH of uncontaminated rain?

pH of 5.6

What is the pH range of natural freshwater?

6.5 to 8.5

What happens to aquatic life at pH levels below 4?

All vertebrates, most invertebrates, and many microorganisms are destroyed.

What materials are affected by acid rain?

Metal and carbonates, causing corrosion.

What chemical reaction occurs when powdered limestone is injected into coal/oil?

CaCO3 is converted to CaO, which reacts with SO2 to form calcium sulfite.

What is the primary pollutant gas formed by incomplete combustion of fossil fuels?

Carbon monoxide (CO)

How does carbon monoxide affect human health?

It binds to iron in hemoglobin, reducing oxygen transport in the blood.

What is the concentration of CO that can significantly reduce blood oxygen capacity?

0.1% CO for a few hours can reduce capacity to 60%.

What is the primary component of smog?

Nitrogen dioxide (NO2)

What reaction produces nitrogen dioxide (NO2) in the atmosphere?

2NO + O2 → 2NO2

What are the two ozone problems in the troposphere?

Excessive ozone in urban environments and depletion in the stratosphere.

What gases form an insulating blanket in the atmosphere?

Water vapor (H2O) and carbon dioxide (CO2)

What is the greenhouse effect?

The process by which H2O and CO2 absorb outgoing infrared radiation, retaining heat.

What role does water vapor play in temperature regulation?

It has high specific heat and helps maintain temperature at night.

What has caused an increase in atmospheric CO2 levels?

Combustion of fossil fuels.

What is the expected increase in CO2 levels by 2050-2100?

Expected to double, leading to a temperature increase of 1-3 °C.

What has been the global air temperature increase over the past century?

0.3 to 0.6 °C