Name _________________________________________
Design Your Own
Date _________________
Class __________________
Do freshwater biomes respond
differently to acid rain?
1(A), 2(E), 2(F), 2(G), 3(A), 3(D), 11(B), 12(F)
Your state happens to be downwind from a volcano that recently ejected large
amounts of ash and sulfur and, as a result, rainwater in your area has been unusually acidic.
You are conducting research for your state’s water resources department to
see how different types of lakes are affected by this acidic rainwater.
Problem
Safety Precautions
Design an experiment that will test how acid rain
impacts algae in a freshwater ecosystem. You might
want to explore a variety of ecosystems found in
different areas of the country or your state, such as a
pond or lake with limestone bedrock or a pond or lake
with granite bedrock.
WARNING: Use caution with the acid rain
samples—they might cause chemical burns. Be sure
to keep lamps away from water sources to avoid a
potential shock hazard.
Possible Materials
Objectives
• Design an experiment to assess the impact of acid
rain on a freshwater pond.
• Conduct the experiment and record data.
• Interpret data and draw conclusions.
pond water
algae samples
limestone chips
acid rain sample
large glass jars (2)
granite gravel
pH test strips
large dropper or pipette
light source
Hypothesis
Use what you know about pH and acid rain to write a hypothesis indicating what impact acid
rain will have on an aquatic environment.
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Lab Manual • Do freshwater biomes respond differently to acid rain ?
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Name _________________________________________
Date _________________
Class __________________
Design Your Own Do freshwater biomes respond differently
to acid rain? CONTINUED
Plan the Experiment
1. Read and complete the lab safety form.
2. Choose the type of gravel you will use to line
your pond: granite or limestone.
3. Decide on a procedure to use when setting up
your pond environment and for testing the pH
of the water.
4. Identify the independent variable, dependent
variable, constants, and control group.
5. Decide how you will record your data and when
you will record it. Design a data table to collect
information about the pH of the water, the time
that has elapsed, and the status of the algae
growing and living in your pond.
6. Determine the length of time needed to observe
your samples.
Check the Plan
1. Be sure that a control group is included in your
experiment, and that the experimental group
varies in only one way.
2. Make sure the teacher has approved your
experimental plan before you proceed.
3. Observe the impact that acid rain has on the
growth of algae in your simulated pond
environment.
4. When you have completed the experiment,
dispose of the pond water as instructed by your
teacher. Be sure to wash your hands with soap
and water after you are done.
Record the Plan
In the space below, write your experimental procedure and make a sketch of your experimental setup.
Lab Manual • Do freshwater biomes respond differently to acid rain ?
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Name _________________________________________
Date _________________
Class __________________
Design Your Own Do freshwater biomes respond differently
to acid rain? CONTINUED
Data and Observations
1. Use the space below to create a data table of your findings, including the length of
time that has passed, the pH of the water each day, and the status of the algae that is
growing in the pond water.
Analyze and Conclude
1. How did the pH of your simulated pond change from day to day?
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2. What impact did the stone lining at the bottom of your pond have on the pH of the
water?
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3. How did the algae in your pond survive? Describe any changes in the appearance of the algae.
Explain possible reasons for what you found.
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Lab Manual • Do freshwater biomes respond differently to acid rain ?
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Name _________________________________________
Date _________________
Class __________________
Design Your Own Do freshwater biomes respond differently
to acid rain? CONTINUED
4. What was the control in your experiment? What did the control show?
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5. Error Analysis What were some possible sources of error in your experiment?
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6. For the peer review process, exchange your procedure and data with a group that used the
same stone as you did and with a group that used the other option. Does comparing your
data with the data from the other groups indicate that the presence of granite as opposed to
limestone can affect the pH in a pond environment? What conclusion can you draw?
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Write and Discuss
Write a short paragraph describing your findings and indicating whether or not they support
your hypothesis. Discuss any questions your results might have raised.
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Inquiry Extensions
1. How does temperature impact the pH of a sample? Design an experiment that
examines the impact of temperature on the pH of pond water.
2. Why should you be concerned about the impact of acid rain on ponds, lakes, and
streams? How does the pH of pond water ultimately impact your life as a teenager in
the United States?
Lab Manual • Do freshwater biomes respond differently to acid rain ?
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