Acid Rain: No Friend to Fish!

Many people think that "Acid Rain" is a relatively new phenomenon. Not so! In fact the term Acid Rain was first used more than 100 years ago by a chemist in Britain!

Acid rain is a term used to describe rain, snow or other precipitation which has been polluted by acids released into the air by natural emissions of sulphur and nitrogen oxides and industrial generators, smelters, industrial mills and motor vehicle exhaust.

It is problem which is serious in many ways, not least that it is capable of lowering the pH of lakes and wetlands hundreds of kilometres from the source of the air-borne emissions. This acidification of wetland habitat can render them useless to many species of fish, aquatic plant life, insects and microorganisms which cannot tolerate high levels of acid. Many lakes and wetlands lose species critical to the food chain of their ecosystem.

The following is an activity you can do with your class to test the pH of the rain in your area. The diagram below indicates the pH of some common substances, as well as that of Acid Rain.

Acid Rain Collection Template PDF

After you have collected your data, place the pH of the rain in the various parts of your town on the scale. How does it measure up? Contact Environment Canada for more information.

Equipment:

• small jars (cleaned & rinsed with distilled water, then capped)s
• test tubes & stoppers (cleaned & rinsed with distilled water, then capped)
• pH paper & colour key distilled water

Procedure:

A.

• have students work in groups, preferably with classmates who live in their neighbourhood as this will be done on their own time
• assign each group a location to take a sample of rain
• when it rains, have the groups place their jars out to capture a few centimetres of rainwater - note the wind direction
• tightly secure the caps
• bring the samples to school

B.

• have each group test the pH of their sample by pouring some of the rain water into a test tube, add pH paper and the stopper
• shake carefully for a minute or so and compare the results with the pH key
• compare results of various locations
• add results to pH scale

Discuss with the class their findings and have them think of possible reasons for their results. Have them complete the following throughout the experiment.

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