Simulating the Effects of Acid Rain
Grade 4
Strand: Earth and Space systems
Topic: Rocks and Minerals
Specific Expectation: Understanding Basic Concepts - describe the effects of wind, water, and ice on the
landscape (e.g., ice breaking rocks into soil), and identify natural phenomena that cause rapid and significant
changes in the landscape (e.g., floods, tornadoes, heavy rainstorms)
Or
Grade 5
Strand: Earth and Space Systems
Topic: Conservation of Energy and Resources
Specific Expectation: Understanding Basic Concepts – describe the water cycle in terms of evaporation,
condensation, and precipitation;
Materials Required:
-
Bottle of Vinegar (1/2 cup per group)
Chalk (two to three pieces per group)
Zip lock bags (2 per group)
Droppers (2 per group)
Plates (2 per group)
Tap water (1/2 cup per group)
Procedure:

Place one piece of chalk in each pan.

Using the dropper drip vinegar onto the chalk on one of the plates in a constant stream.

Using the dropper drip water onto the chalk on the second plate in a constant stream.

Discuss the following observation questions as a class:
1. What happened to the chalk?
2. How does this model show what might happen to structures due to acid rain?
3. Are there any natural causes of acid rain?
Scientific Explanation:
Acid rain is caused mostly by the combustion of fossil fuels containing sulfur and nitrogen. When
sulphur and nitrogen are combusted, sulphur dioxide and nitrogen oxides are created and released into the
atmosphere. Once these gases come in contact with water they become acids (Sulphuric acid and Nitric acid).
This can happen either through wet deposition when rain, sleet or snow remove the gases from the air or
through dry deposition when particles are deposited and absorbed into surfaces and later converted into acids
when they come into contact with water.
Coal power plants, electricity generation, driving a car, volcanoes and thunderstorms all contribute to
acid rain. While there are natural causes of acid rain as mentioned, 90% of harmful emissions are a result of
man-made sources.
Acidity of rainwater is measured by the pH scale. It ranges from 0 which is highly acidic to 14 which is
highly alkaline (basic). The scale point 7 is neutral. Clean rain measures at pH 5.6 while acid rain is anything
measuring between pH 5 and pH 0.
Acid rain has an adverse effect on the natural environment including forests, freshwaters and soils. It not
only kills insect and aquatic life forms but also causes damage to buildings and has impacts on human health.
Acid rain destroys the surface of trees and depletes essential nutrients in the soil greatly impacting plant
germination and reproduction, causing vulnerability to disease and stunting its growth. It increases the level of
acidity in water sources which inhibits the ability for natural mechanisms to cope. Gradually the most fragile
creatures and life forms begin to die. Lastly, acid rain damages buildings through corrosion and fracturing.
Great structures such as the Taj Mahal and the Washington Monument buildings have all suffered the harmful
effects of acid rain. Buildings made of limestone are particularly impacted.
In order to mimic the effect of acid rain on the environment specifically on rock (limestone) we used
vinegar and chalk. It may take a considerable amount of time to see the visible effects of acid rain yet the
reaction of vinegar and chalk is instant and illustrates the same concept. The reaction of vinegar and chalk is an
example of an acid- base reaction (neutralization). Vinegar, the acid, has a pH level of 3 while the chalk also
known as calcium carbonate is a base at pH 8. When they are combined the chalk starts to bubble and foam up.
The acid breaks apart the calcium carbonate and produces calcium and carbon dioxide gas. The bubbles you see
during the reaction are carbon dioxide. On the surface of the vinegar are small pieces of chalk which have been
neutralized.
Opportunities and Other Considerations:

This experiment could also be conducted using a piece of limestone over a longer period of time.

This experiment/demonstration is intended to be a motivating starting point for students to get interested
in this topic. However, it is important to not over-emphasize acid rain over other effects of pollution on
the landscape.

This activity can easily connect to many different topics such as environmental degradation, wetlands
and forests, and even animals and habitats. Acid rain has extensive impact on the planet and be
connected to a number of different topics.
References:
Acid Rain. (2002).The Green Lane, Environment Canada. Retrieved October 21, 2008 from
http://www.ec.gc.ca/acidrain/
Junior Science Experiments on File Volume 2 (Facts on File Inc.)
Kennedy, I.R. 1992. Acid Soil and Acid Rain. New York: John Wiley and Sons Inc.
Kimmins, Hamish. 1992. Balancing Act: Environmental Issues in Forestry. Vancouver: UBC Press.
Likens, Gene. (2007). Acid Rain. Encyclopedia of the Earth. Retrieved October 21, 2008 from
http://www.eoearth.org/article/Acid_rain