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Products from Oil

How does Oil affect the Environment?

Fossil fuels are burnt on a huge scale.

What causes Acid Rain?

Coal, oil and natural gas contain sulfur. When
they are burnt in a power station the sulfur oxidises
(reacts with oxygen) to form sulfur dioxide gas.

sulfur + oxygen  arrow  sulfur dioxide.
S(s) +    O2(g)   arrow         SO2(g) 

Sulfur dioxide gas is acidic, poisonous,
and smells like burnt matches.

Sulfur dioxide can be removed from the burnt waste gases
(called flue gases) in the power station chimney by wet scrubbing.
Calcium oxide (quicklime) or calcium carbonate (limestone)
 is powdered and mixed with water and sprayed into the chimney.
It reacts with the sulfur dioxide to produce calcium sulfite
which can then be reacted with oxygen to make calcium sulfate.
Calcium sulfate (called gypsum) is used to make plaster.

What is Acid Rain?

If sulfur dioxide gets into the atmosphere it reacts with water
and oxygen in the air to form a dilute solution of sulfuric acid.
This sulfuric acid is the main pollutant in acid rain.
Natural rain is slightly acidic due to dissolved carbon dioxide.
Natural rain has a pH of 5·5, acid rain has a pH of 4.
The second most important pollutant in acid rain is nitric acid.

What are the Effects of Acid Rain?

Acid rain kills trees. It runs into rivers and gathers in lakes.
Eventually, lakes become too acidic. Plants and fish begin to die.
Acid rain reacts with limestone and damages limestone buildings.

Powdered limestone or slaked lime can be added
to soils or lakes to make them less acidic.
It would be better if we could avoid or
reduce pollutant gas emissions in the first place.

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