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Wetland Curriculum Resource
Unit 5. Environmental Issues -

(Level: 11 acad :: Acid Deposition)

Purpose: To observe the effects of sulphur dioxide on plants.

What You Need: 2 healthy bean plants :: 1 L dilute sulphuric acid :: sodium sulphite :: 2 plastic bags (clear if possible) with twist ties :: small beaker :: safety goggles :: napkin or Kleenex :: graduated cylinder

What You Do:

Before this activity: Prepare the dilute sulphuric acid. Mix 5.5 ml of concentrated sulphuric acid slowly with 500 ml of cool water. Let stand, and then dilute to 1 L.

WARNING: Always pour acid into water. Never pour water into acid. Wear goggles.

  1. Put on the safety goggles. Sulphuric acid can be harmful if it comes in contact with your skin or eyes. Measure 30 ml of dilute sulphuric acid and pour it into the small beaker.
  2. Wrap 2 g of sodium sulphite tightly in a napkin.
  3. Place both bean plants in separate plastic bags. Set the beaker with the acid in the bag with one of the bean plants.
  4. Under a fume hood, place the sodium sulphite wrapped in the napkin, in the beaker of sulphuric acid. The combination of these chemicals produces sulphur dioxide. Close the bag quickly and tie the bag closed. DO NOT BREATHE THE FUMES.
  5. Close and tie the other bag with the bean plant with no chemicals. Observe the closed bags for a period of 24-48 hours.


  1. What effect does the sulphur dioxide have on the bean plant?
  2. What are the human sources of sulphur dioxide in the atmosphere?
  3. What are the natural sources of sulphur dioxide in the atmosphere?
  4. How is sulphur dioxide converted to acid rain?
  5. What can be done to control the human sources of sulphur dioxide in the atmosphere?
  6. In what stage of their life cycle are amphibians most affected by acid rain. Why?


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