What is Acid Rain?

  -        Snow, rain or fog that’s polluted by acid and damages the environment

What chemicals make rain acidic, and how does it happen?

  -         Two chemicals that make rain acidic are sulfur dioxide (SO₂) SO₂+OH -> H₂SO₄  and nitrogen oxide (NO_x) NO₂+OH -> HNO₃ 

     -         Substances are released and can be carried over long distances

  Where do these chemicals come from?

  -         SO₂ is a byproduct of burning fossil fuels

  -         Ore smelting, coal-fire powered generators, and natural gas processing are main contributors

 -         NO_x emissions come from the fuels in motor vehicles, residential and commercial furnaces, industrial and electrical utility boilers and engines, and other equipment.

 How do we measure the acidity of rain?

  -         With the pH scale

 What is pH?

  -         It's used to measure the amount of acid in a liquid like water

    -         A smaller number on the pH scale means the substance is more acidic

  -         When a small number changes there are larger changes in the acidity  

The pH scale and a list various things that correspond to the different pH levels.

What is the pH of normal rain, and at what level does the pH become dangerous?

-         pH of normal rain is around 5.5 (slightly acidic)

-         pH becomes dangerous at about 4.0

http://www.ec.gc.ca/acidrain/acidfact.html

http://olp.swlauriersb.qc.ca/webquest/acidrain/acidnews2.htm

Home