Learning About
Acid Rain
A Teacher's Guide
For Grades 6
Through 8
£EPA
United States
Environments! Protection
Agency
CLEANAIR
MARKET PROGRAMS
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•••••
United States Environmental Protection Agency
Office of Air and Radiation
Office of Atmospheric Programs
Clean Air Markets Division (6204])
1200 Pennsylvania Ave., NW
Washington, D.C. 20460
EPA 430-F-08-002
April 2008
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ofthe
Acid Rain
1970 -1994
Progra
7970
Twenty million people
celebrate the first
Earth Day.
7970
The Clean Air
Act (CAA)
is passed.
7977
Congress strengthens
the CAA and includes
requirements for S02
pollution control at
power plants.
797S
The National Atmospheric Deposition Program/National
Trends Network (NADP/NTN) begins monitoring sulfur
and nitrogen deposition to ecosystems.
7980
The National Acid Precipitation
Assessment Program (NAPAP),
mandated by Congress, begins
study on acid rain.
7980
Lake acidification and fish
loss in the Adirondacks,
Green Mountains, and Sierra
Nevada make national news.
7986
The United States and Canada begin
study of cross-border acid rain
transport. The United States is called
upon to reduce emissions of S02 and
NOx, especially from coal-burning
power plants.
7987
The Clean Air Status
and Trends Network
(CASTNET) is
established to
monitor dry
deposition.
7990
Congress strengthens the CAA and
establishes the Acid Rain Program
using a market-based approach to
reduce S02 from power plants by
more than 50 percent.
7993
EPA publishes acid rain
regulations, and the
Chicago Board of Trade
holds first auction of
S02 allowances.
7994
Projected costs of compliance
re-estimated by the
Government Accountability
Office and the Electric Power
Research Institute at less than
half of original estimates.
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1995 - 1999
2000 - 2005
7995
Phase I of Acid Rain Program implementation
begins. S02 emissions fall to 5 million tons
below 1980 levels. Acidity of rainfall in the
eastern United States drops 10 to 25 percent.
2000
Phase II of Acid Rain Program
begins, regulating additional
smaller/cleaner plants and
requiring further reductions
in N0xand SO,.
• 7996
About 150 of the largest
coal-fired power plants
begin to implement Acid
Rain Program NOX
requirements.
2007
Introduction of the
On-line Allowance
Tracking System
begins an era of
paperless allowance
transfer recording.
2002
EPA begins electronic
audit process to
supplement existing
rigorous monitoring
program.
7997
More than 80
percent of affected
companies have
engaged in private
allowance
transactions.
2003
Lakes and streams in
the Adirondacks, Upper
Midwest, and Northern
Appalachian Plateau
show signs of recovery.
2004
Acid Rain Program sources
emit 34 percent less S02
and 43 percent less NOX
than in 1990, despite a
34 percent increase in
fuel usage.
7998
Regulatory revisions
enhance efficiencies of
compliance and
administration. Nearly
10 million economically
significant allowance
transfers take place.
7999
Allowance
banking peaks.
S02 early reduc-
tions total over
11 million tons.
2005
New study estimates 2010 annual Acid Rain
Program benefits at $122 billion and annual
costs at $3 billion. According to the 2005 NAPAP
report, further emission reductions are neces-
sary to achieve broader environmental recovery.
EPA promulgates Clean Air Rules to further
reduce S02, NOX, and for the first time, mercury.
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Contents
PURPOSE. . 2
INTRODUCTION 3
OBSERVATIONS ABOUT ACIDITY . 5
DEFINING ACID RAIN
Air Pollution Causes Acid Rain
Acid Precipitation
Dry Deposition ... 7
Acid Rain Is A Problem That Can Travel 7
Natural Acids 8
EFFECTS OF ACID RAIN ON ECOSYSTEMS. , 9
Forests... 9
Acid Rain On The Forest Floor 10
Ponds, Lakes, And Streams ... n
EFFECTS OF ACID RAIN-CAUSING POLLUTANTS ON HUMANS . 12
EFFECTS OF ACID RAIN ON MAN-MADE MATERIALS. . 13
WHAT IS BEING DONE . 14
The Acid Rain Program 14
Monitoring 16
Alternative Ways Of Producing Energy . . 17
WHAT YOU CAN DO TO HELP . 18
To Prevent Acid Rain ... .18
To Address Other Environmental Problems ... .19
EXPERIMENTS 20
Measuring With pH Paper 20
Measuring With pH Meters ... ... 20
Tips 21
Safety In The Laboratory 21
Recording Observations 22
Experiment i: Measuring pH. . 23
Experiment 2: Determining The pH Of Common Substances 24
Experiment 3: Making A Natural pH Indicator ... 25
Experiment 4: Measuring The pH Of Natural Water ... 26
Experiment 5: Measuring Soil pH. . ... 27
Experiment 6: Soil Buffering 28
Experiment 7: Observing The Influence Of Acid Rain On Plant Growth ... 29
Experiment 8: Looking At Acid's Effects On Metals 30
Experiment 9: Observing The Influence Of Acid Rain On Marble And Limestone 31
EXPERIMENT ANSWERS 33
ACTIVITIES . 37
GAMES . 39
Crossword Puzzle 39
Word Search 40
Game Answers 41
ADDITIONAL RESOURCES 42
GLOSSARY . 43
PARTICIPATION AND COMPLETION CERTIFICATE 47
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Purpose
Acid rain is a complex environmental
problem which affects the United States
and many other countries around the
world. The United States Environmental
Protection Agency (EPA) was established
in 1970 to address environmental issues,
such as acid rain. Through its programs,
EPA works to protect human health and
the environment in the United States by
developing and enforcing regulations
and studying environmental conditions.
In addition, EPA is committed to inform-
ing the public about environmental
topics and its efforts to solve them
through written materials and its Web
site (www.epa.gov). EPA frequently
receives requests for information about
environmental problems from school
systems, teachers, and individuals. Acid
rain is one of the most frequently
requested topics. As part of EPA's public
outreach on acid rain, EPA first devel-
oped this guide in 1990. This revised
guide is designed to help students
better understand the science, cause
and effect, and regulatory and citizen
action that are part of understanding
and addressing acid rain.
This book is intended for teachers of
students in 6th-8th grade. It is written at
a 6th grade level and the language,
concepts, and experiments may need to
be adapted for other grades accordingly.
After reading the guide and doing some
of the experiments and activities, we
hope that you and your students will
have a better understanding of acid rain
and the problems it causes, as well as a
greater interest in its resolution and in
applied environmental science.
In addition to this teacher's guide, EPA
has many other publications with
information on research, monitoring,
regulation, and other aspects of the acid
rain problem. If you are interested in
learning more, resources are available at
www.epa.gov/airmarkets. This guide,
"Learning About Acid Rain: A Teacher's
Guide for Grades 6 Through 8," is avail-
able online at www.epa.gov/acidrain
/education/teachersguide.pdf. Printed
copies are available for free through the
Acid Rain Hotline (202-343-9620).
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Introduction
When harmful substances are released into
the air, it causes pollution.
Humans make use of many things found
in nature. For example, we use trees to
build our homes and cotton to make our
clothes. Things that are not made by
people, but instead occur naturally, are
called NATURAL RESOURCES. Some
examples of natural resources are
plants, minerals, and water. All of these
things are important to humans because
they provide us with the materials we
need to make the things we use every-
day. Some of the products made from
natural resources are obvious to us, like
the timber and stone that make build-
ings. Other natural resources are not as
noticeable, like the underground water
table where our drinking water comes
from. Natural resources that humans use
to generate electricity are called ENERGY
RESOURCES. Most energy in the United
States comes from burning FOSSIL FUELS
such as coal, oil, and natural gas. Coal,
oil, and natural gas are called fossil fuels
because they were formed millions of
years ago from dead plants and animals.
People burn fossil fuels for many
reasons. We burn oil and coal to make
the electricity that we need to light
buildings and run appliances like televi-
sions and computers. We burn gas to
heat our homes and to power cars,
buses, and airplanes. Many human
activities, including the burning of fossil
fuels, cause POLLUTION. Pollution is the
release of harmful substances called
POLLUTANTS into the ENVIRONMENT.
The air pollution created when fossil
fuels burn does not stay in the air
forever. Instead it can travel great
distances, and fall to the ground again
as dust or rain. When airborne chemi-
cals and pollutants fall to the Earth,
or deposit, it is called DEPOSITION.
ACID RAIN forms when clean rain comes
into contact with pollutants in the air,
like SULFUR DIOXIDE (S02), CARBON
DIOXIDE (C02), and NITROGEN OXIDES
(NOX). Although sulfur dioxide and
carbon dioxide occur in the air natu-
rally, burning fossil fuels adds more of
these chemicals to the air. When these
pollutants are released into the air,
they mix and react with water, oxygen,
and other chemicals to form acid
rain. Acid rain then falls to the Earth
where it can damage plants, animals,
soil, water, and building materials.
TERMINOLOGY
Natural Resources All the parts of
the Earth that are not human-made
and which people use, like fish,
trees, minerals, lakes, or rivers.
Energy Resources Natural
resources that can be used to
make heat, electricity, or any
other form of energy. The most
commonly used energy resources
are fossil fuels (coal, oil, and
gas), but the sun, wind, and
anything else that makes energy
are also energy resources.
Fossil Fuels Oil, natural gas, and
coal. Fossil fuels were made
in nature from ancient plants
and animals, and today we
burn them to make energy.
Pollution The release of harmful
substances into the environment.
Pollutants Chemicals or
other substances that are
harmful to or unwanted in the
environment. Some examples
of pollutants are sulfur dioxide
(S02), nitrogen oxides (NOX),
ozone, and particulate matter.
Environment The air, water,
soil, minerals, organisms, and
all other factors surrounding
and affecting an organism.
Deposition When chemicals
like acids or bases fall to the
Earth's surface. Deposition can
be wet (rain, sleet, snow, fog)
or dry (gases, particles).
Acid Rain Rain that has become
acidic by contact with air pollution.
Other forms of precipitation,
such as snow and fog, are also
often included in the term acid
rain or acid wet deposition.
Sulfur Dioxide (S02) A naturally
occurring gas made of sulfur
and oxygen that is also released
when fossil fuels are burned.
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TERMINOLOGY
Carbon Dioxide (C02) A naturally
occurring gas made of carbon
and oxygen. Sources of carbon
dioxide in the atmosphere
include animals, which exhale
carbon dioxide, and the burning
of fossil fuels and biomass.
Nitrogen Oxides (NOX) A family
of gases made up of nitrogen
and oxygen commonly released
by burning fossil fuels.
Paniculate Matter Tiny solid
particles or liquid droplets
suspended in the air.
Ozone A chemical that is made
of three oxygen atoms joined
together, and found in the Earth's
atmosphere. There are two kinds
of ozone: good ozone, and bad
ozone. Good ozone is found
high in the Earth's atmosphere,
and prevents the sun's harmful
rays from reaching the Earth.
Bad ozone is found low to the
ground, and can be harmful to
animals and humans because it
damages our lungs, sometimes
making it difficult to breathe.
Emissions The gases that
are released when fossil
fuels are burned.
Ozone Layer The layer of ozone
that shields the Earth from
the sun's harmful rays.
Greenhouse Gases Gases that occur
naturally in the Earth's atmosphere
and trap heat to keep the planet
warm. Some examples are carbon
dioxide, water vapor, halogenated
fluorocarbons, methane,
hydrofluorocarbons, nitrous
oxide, perfluoronated carbons,
and ozone. Some human actions,
like the burning of fossil fuels,
also produce greenhouse gases.
Despite its name, acid rain does not
burn and cannot directly harm people.
However, the pollutants that cause acid
rain, especially S02 and NOX, can react
with other pollutants in the air, forming
substances like PARTICULATE MATTER and
ground level OZONE, which can some-
times make people sick.
While the "Acid Rain Teacher's Guide"
focuses mainly on the issue of acid rain,
the EMISSIONS that result from the
burning of fossil fuels have many other
environmental consequences in addition
to causing acid rain. Chemicals like NOX,
produced by the burning of fossil fuels,
combine with other chemicals in the
atmosphere to form ground level ozone.
Although the planet needs an OZONE
LAYER for protection from the sun's
harmful ultraviolet rays, ozone can be
dangerous when it forms low to the
ground because it hurts our lungs and
sometimes makes it difficult to breathe.
Other chemicals that are released by the
burning of fossil fuels are GREENHOUSE
GASES. Greenhouse gases occur naturally
in the Earth's atmosphere, keeping the
planet warm enough for humans to live.
Without greenhouse gases, the planet
would be an average 60° F colder than it
is today (brrr!). However, since the
Industrial Revolution, human activity,
such as the burning of fossil fuels, has
increased the amount of greenhouse
gases in the atmosphere. By increasing
the levels of greenhouse gases, human
activities are affecting the mix of gases
in the atmosphere. This is causing the
Earth's temperature to rise. For more
information on climate change and its
causes and effects, check out
www.epa.gov/climatechange.
The consequences of air pollution are
important to understand because air
pollution can be carried long distances
and affect large areas. This means that
pollution from a town hundreds of miles
away may be affecting your community.
Scientists, engineers, and researchers
monitor the effects of pollution on the air,
forests, water, and soil. They are invent-
ing ways to reduce the amount of
pollution that enters the environment
and to prevent new damage in the future.
Where Our Electricity
Comes From
3.0%
1.7%
Other Energy Petroleum
Sources
of our electricity in the United States is
made by coal power plants.
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Observations About Acidity
ACIDIC and BASIC are two extremes that
describe chemicals, just as hot and cold
are two extremes that describe tempera-
ture. Mixing ACIDS and BASES can cancel
out their extreme effects; much like
mixing hot and cold water can even out
the water temperature. A substance that
is neither acidic nor basic is NEUTRAL.
The pH SCALE measures the acidic or
basic level of a substance. The pH scale
ranges from o to 14. A pH of 7 is neutral,
while a pH less than 7 is acidic and a pH
greater than 7 is basic.
The pH Scale
Pure water is neutral. However, when
chemicals are mixed with water, the
mixture can become either acidic or
basic. Examples of acidic substances are
vinegar and lemon juice. Laundry
detergents and ammonia are examples
of basic substances. Chemicals that are
very basic or very acidic usually change
or alter whatever they meet. Substances
that have this property are called
REACTIVE. You should be careful with
these kinds of chemicals because they
can cause severe burns and are often
toxic if swallowed. For example, house-
hold drain cleaners often contain lye, a
very basic chemical that is reactive and
could burn you.
Increasingly
Acidic
Neutral
) Vinegar
I Cola 4
i
Coffee 5
Milk 6
Increasingly
Basic
Baking Soda
Sea Water
Water ~> Neutral
Acid Rain
Adult Fish Die
Fish Reproduction Affected
Normal Range of Precipitation
Normal Range of Stream Water
10
UJ Ammonia 12
13
Lye
14
TERMINOLOGY
Acidic Describes a substance
with a pH less than 7.
Basic Describes a substance with
a pH greater than 7. Another
word for basic is alkaline.
Acid Any of a large group of
chemicals with a pH less than
7. Examples are battery acid,
lemon juice, and vinegar.
Base Any of a large group
of chemicals with a pH
greater than 7. Examples are
ammonia and baking soda.
Neutral A substance that is
neither an acid nor a base
and has a pH of 7. Neutral
substances can be created by
combining acids and bases.
pH Scale The range of units that
indicate whether a substance
is acidic, basic, or neutral. The
pH scale ranges from o to 14.
Reactive Having the tendency
to chemically combine with
something else and change its
form. For example, a strong acid is
highly reactive with a strong base.
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Defining Acid Rain
TERMINOLOGY
Atmosphere The air or gases
that surround a planetary
body such as the Earth.
Sulfuric Acid An acid that can be
produced in the atmosphere from
sulfur dioxide, a pollutant that
results from burning fossil fuels.
Nitric Acid An acid that can be
produced from nitrogen oxide,
a pollutant that results from
the burning of fossil fuels.
Precipitation Water falling to
the Earth. Mist, sleet, rain, hail,
fog, and snow are the most
common kinds of precipitation.
Hydrologic Cycle The movement of
water from the atmosphere to the
surface of the land, soil, and plants
and back again to the atmosphere.
Hydrologic Cycle
Acid rain is rain that is more acidic than
it should be. Acid rain is a complicated
problem affecting soil and water chemis-
try, as well as the life cycles of plants
and animals on land and in the water. In
addition, weather conditions contribute
to air pollution and cause acid rain to
spread vast distances.
Air Pollution Causes
Add Rain
Scientists have discovered that air
pollution from the burning of fossil fuels
is the major cause of acid rain. Power
plants and factories burn coal, oil, and
natural gas to produce the electricity we
Evaporation from
Lakes, Rivers, Oceans
need to do all kinds of things, like light
our homes. Cars, trucks, and airplanes
also run on gasoline, a fossil fuel.
When we burn things, they do not
disappear. For example, when you burn
a log in a campflre, ash is left. But what
happened to the rest of the log? Water
from the log becomes vapor and enters
the air. Burning wood also releases
chemicals and particles into the air. The
same thing happens when we burn
fossil fuels. Burning fossil fuels sends
smoke and fumes into the ATMOSPHERE,
or the air above the Earth. In the air,
these pollutants combine with moisture
to form acid rain. The main chemicals in
air pollution that create acid rain are
sulfur dioxide (S02) and nitrogen oxides
(NOX). Acid rain usually forms high in the
clouds where S02 and NOX react with
water and oxygen. This forms SULFURIC
ACID and NITRIC ACID in the atmosphere.
Sunlight increases the speed of these
reactions, and therefore the amount of
acid in the atmosphere. Rainwater,
snow, fog, and other forms of
PRECIPITATION then mix with the sulfuric
and nitric acids in the air and fall to
Earth as acid rain.
Acid Precipitation
Water moves through the air, streams,
lakes, oceans, and every living plant and
animal in the HYDROLOGIC CYCLE, shown
in the image to the left. In that cycle,
water EVAPORATES from the land and sea
and becomes a gas in the atmosphere.
Water in the atmosphere then
CONDENSES, or becomes liquid again,
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Tall smokestacks send pollution high into the air. The longer the pollution is in the air, the
greater the chances that the pollutants will form acid rain.
and forms clouds. Clouds release the
water back to the Earth as rain, sleet,
hail, snow, or fog. When water droplets
form and fall to the Earth they pick up
particles like the dust and chemicals
that float in the air. Even clean, unpol-
luted air contains particles such as dust
or pollen. Clean air also contains natu-
rally occurring gases such as carbon
dioxide (C02). The interaction between
the water droplets and the C02 in the
atmosphere gives rain a pH of 5.6,
making even clean rain slightly acidic.
However, when rain contains pollutants,
especially S02 and NOX, the rainwater can
become very acidic.
Dry Deposition
Acid rain does not account for all of
the acidity that falls back to Earth from
pollutants. About half of the acidity in
the atmosphere is deposited onto
buildings, cars, homes, and trees-
anything!-as particles and gases. This
process is called DRY DEPOSITION. In
some instances, these gases and
particles can damage or alter the things
on which they settle. Dry deposition
(gases and particles) is sometimes
washed from trees and other surfaces
by rainstorms. When that happens, the
RUNOFF water contains acid from acid
rain and dry deposition, making the
combination more acidic than the falling
rain alone. The combination of acid rain
(wet deposition) plus dry deposition is
called ACID DEPOSITION.
Acid Rain Is A
Problem That
Can Travel
The chemical reactions that cause acid
rain can take several hours to several
days to occur. Years ago, when smoke-
stacks were only a few stories high,
pollution from smokestacks usually
stayed near the ground and settled on
the land nearby. This caused unhealthy
conditions for people, plants, and
animals near those smokestacks. To
reduce this pollution, the government
TERMINOLOGY
Evaporate To change
from liquid into gas.
Condense To change from gas
or vapor to liquid form.
Dry Deposition The falling of
small particles and gases to the
Earth without rain or snow.
Runoff Water that flows off
land into lakes and streams.
Acid Deposition Acidic material
that falls from the atmosphere
to the Earth in either wet
(rain, sleet, snow, fog) or dry
(gases, particles) forms.
Dry deposition can be washed
away from surfaces such as
buildings and cars during
rainstorms.
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Volcanoes are a natural
source of acid.
A geyser, like the one shown
here in Yellowstone National
Park, is also a natural source
of acid.
passed laws for the construction of very
tall smokestacks. At that time, people
thought that if the pollution were sent
high into the air it would no longer be a
problem. Scientists now know that this
is incorrect. In fact, sending pollution
high into the sky increases the time that
the pollution stays in the air. The longer
the pollution is in the air, the greater the
chances that the pollutants will form
acid rain. In addition, the wind can carry
these pollutants for hundreds of miles
before they become joined with water
droplets to form acid rain. For that
reason, acid rain, or wet deposition, can
be a problem in areas far from sources
of pollution. Dry deposition is usually
greater near the cities and industrial
areas where the pollutants are released.
Formation of Acid Rain
Movement
of Pollutants
Natural Adds
There are also natural sources of acids
such as volcanoes, geysers, and hot
springs. Nature has developed ways of
recycling these acids by absorbing and
breaking them down. These natural
acids contribute to only a small portion
of the acidic rainfall in the world today.
In small amounts, these acids actually
help dissolve nutrients and minerals
from the soil so that trees and other
plants can use them for food.
Unfortunately, the large amounts of
acids produced by human activities
overload this natural acidity and throw
ecosystems off balance.
Gaseous
Pollutants in
Atmosphere
Particulate-
Pojlutants in
Atmosphere
Pollutants in
Cloud Water and
Precipitation
o
S
8
Q.
01
Q
8
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Effects Of Acid Rain On Ecosystems
Acid rain and the air pollution that
causes it can severely damage
ECOSYSTEMS. An ecosystem is all the
living and nonliving things in an area, as
well as the interactions between them.
Ecosystems come in all sizes. An entire
forest is an ecosystem, but so is a single
tree. Some scientists even consider the
entire Earth an ecosystem. The study of
ecosystems is called ECOLOGY. Ecologists
study things like predator-prey relation-
ships, how nutrients are taken from the
soil into trees, or the kinds of bacteria
found in a pond. Every ecosystem is
very interconnected, and the organisms
that live there rely heavily on each
other. For example, ecosystems have
food webs, where species depend on
one another for food. If any one animal
is affected, so are several others. This is
how acid rain can affect entire ecosys-
tems. Acid rain may only damage a few
organisms in an ecosystem, but every-
thing else is indirectly affected. The
damage acid rain causes can also take
years, or even decades to reverse.
Forests
Acid rain causes significant damage to
forests. It directly affects trees and other
plants which are important to the
ecosystem as a whole because they are
PRIMARY PRODUCERS. Primary producers
are organisms that produce their own
food through PHOTOSYNTHESIS, a series
of chemical reactions that convert water
into sugar using light from the sun to
provide energy. Plants and some micro-
scopic animals have this ability. Plants
Sugar Maple leaves turn brilliant shades of red, orange, and yellow in the fall.
People from all over the United States and the world travel to New England to see
colorful autumn leaves like those of the Sugar Maple.
are important to ecosystems because
they feed everything else, and provide
important HABITAT for other animals. If
trees and plants are damaged by acid
rain, the effects are felt throughout the
entire ecosystem.
Acid rain causes trees in forests to grow
more slowly, and in some sensitive
species it can even make the leaves or
needles turn brown and fall off. Red
Spruce and Sugar Maple, two species of
trees found mainly in the East and in
New England, are very susceptible to
acid rain damage. Acid rain damages
trees by dissolving the calcium in the
soil and in the leaves of trees. This hurts
the tree, because calcium is a mineral
that trees need to grow. Once the
calcium is dissolved, the rain washes it
away so the trees and other plants
cannot use it to grow. Acid rain washes
other minerals and nutrients from the
soil in a similar fashion, causing
NUTRIENT DEFICIENCY. This is why acid
rain can cause trees to grow more slowly.
TERMINOLOGY
Ecosystem All the living and
nonliving things in an area, as well
as the interactions between them.
Ecology The study of ecosystems.
Someone who studies ecology
is called an ecologist.
Primary Producers Organisms
that use photosynthesis to
produce their own food. All
plants are primary producers.
Primary producers are the
base of the food chain because
they feed everything else.
Photosynthesis The process that
plants use to convert sunlight
to energy to live and grow.
Habitat The place where a plant
or animal lives and grows, such
as a forest, lake, or stream.
Nutrient Deficiency When a living
thing lacks the vitamins and
minerals it needs to survive.
9
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TERMINOLOGY
Aluminum A silvery-white
metal; it is the most abundant
metal in the Earth's crust.
Haze When particles of dust,
pollen, or pollution make the air
less clear, and limit visibility.
Neutralize To combine acids
and bases to make a neutral
substance or solution. For
example, acidic water can be
neutralized by adding a base.
Buffering Capacity The ability of a
substance to resist changes in pH
when acids or bases are added.
Buffer A substance, such as soil,
bedrock, or water, capable of
neutralizing either acids or bases.
Rain falls through the trees to the forest floor
and runs into streams, rivers, and lakes.
Nutrient deficiency causes other prob-
lems for trees and plants. The lack of
nutrients weakens the trees, and makes
them more sensitive to the cold. A
well-nourished tree in healthy soil will
survive even a very cold winter with
little difficulty, but a tree already weak-
ened by a mineral deficiency can die
during a cold winter. The weakened
trees and plants are also more sensitive
to insects and disease.
At the same time, acid rain causes
the release of substances such as
ALUMINUM from the soil. Aluminum can
be very harmful to trees and plants.
Once released into soil, aluminum can
end up in streams, rivers, and lakes,
where it can harm or even kill fish. Less
aluminum is released when the rainfall
is cleaner.
The pollution that causes acid rain also
causes HAZE by scattering light back
towards the sky. Haze reduces the
amount of light available for plants to
use in photosynthesis. Since photosyn-
thesis is the base of the food chain, acid
rain can cause problems with the move-
ment of nutrients to other organisms in
ecosystems that are already impacted.
Further reducing the amount of photosyn-
thesis are acid fogs. Fog can often be
more acidic than rainfall. When leaves are
frequently bathed in acid fog, their
protective waxy coating can wear away.
The loss of this coating damages the
leaves and creates brown spots. The
leaves are then unable to use photosyn-
thesis to turn the energy in sunlight into
food for growth. When leaves are
damaged, they cannot produce enough
food energy for the tree to remain healthy.
Acid Rain On The
Forest Floor
A spring shower in the forest washes
leaves and the rain falls through the
trees to the forest floor below. Some of
the water soaks into the soil. Some
trickles over the ground and runs into a
stream, river, or lake. Soil sometimes
contains substances, like limestone, that
buffer acids or bases. Some salts in soil
may also act as buffers. The soil may
NEUTRALIZE, or make less acidic, the acid
rainwater. This ability of the soil to resist
pH change is called BUFFERING CAPACITY.
A BUFFER resists changes in pH. Without
buffering capacity, soil pH would change
rapidly. Midwestern states like Nebraska
and Indiana have soils that are well
buffered. Places in the mountainous
northeast, like New York's Adirondack
Mountains, have soils that are less able
to buffer acids. Other soils, like those in
10
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the Southern Appalachian Region, hold
acids from acid rain, making them more
susceptible to damage from acid rain.
Since there are many natural sources of
acids in forest soils, soils in forest areas
are especially sensitive to effects from
acid rain.
Ponds, Lakes,
And Streams
The effects of acid rain are most clearly
seen in AQUATIC environments such as
streams, lakes, and marshes. Acid rain
flows to streams, lakes, and marshes
after falling on forests, fields, buildings,
and roads. Acid rain also falls directly on
aquatic habitats.
Most lakes and streams have a pH
between 6 and 8, because the buffering
capacity of soil usually neutralizes
slightly acidic, clean rain. Lakes and
streams become acidic (pH value goes
down) when the rainwater itself is so
acidic that the surrounding soil cannot
buffer the rain enough to neutralize it.
For this reason, some lakes in areas
where soil does not have a lot of
buffering capacity are naturally acidic
even without acid rain. In areas like the
northeastern United States where soil
buffering is poor, acid rain has made
already slightly acidic lakes very acidic,
with some lakes having a pH value of
less than 5. As lakes and streams
become more acidic, the numbers and
types of fish and other aquatic plants
and animals that live in these waters
decrease. Some types of plants and
animals are able to tolerate acidic
waters. Others, however, are acid-sensi-
tive and will leave or die as the pH
declines. Some acidic lakes have no fish,
because at pH 5 most fish eggs cannot
hatch. At lower pH levels, adult fish can
die. Substances like aluminum that wash
into the water from the soil can also
harm and kill fish.
pH Tolerance Chart on Aquatic Life
pH 6.5 pH 6.0 pH 5.5 pH 5.0 pH 4.5 pH 4.0
Snails have a very low pH
tolerance of 6.0.
ERMINOLOGY
Tf
Aquatic Relating to water.
Some animals can survive
in water that is moderately
acidic, while other animals
can only live in water that is
near neutral. An animal that
can survive in moderately
acidic water is said to have a
high tolerance for acidity. The
chart to the \e]t shows the pH
tolerance of various animals.
Where the boxes are gray,
the animals can survive, but
where the boxes are black, the
animals can no longer tolerate
the acidity and die. From the
chart, you can see that frogs
have a high tolerance for
acidity, while clams and snails
have a low tolerance.
11
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TERMINOLOGY
Respiratory Illness Diseases
affecting the organs we use to
breathe. Asthma, bronchitis,
and pneumonia are examples
of respiratory illnesses.
Respiratory System The organs
in our body involved with
the process of breathing.
Effects Of Acid Rain-Causing
Pollutants On Humans
These are photos from the Great Smoky Mountains National Park in Tennessee and
North Carolina. The photo on the left, taken January 27, 7986, shows what the park
looks like on a clear day, or a day where there is little pollution present to reduce
visibility. The photo on the right, taken August 5, 7986, shows the same view on a
hazy day, when the air is filled with aerosols.
Air pollution, shown here
in New York City, can cause
health problems.
Acid rain looks, feels, and tastes just
like clean rain. Walking in acid rain, or
even swimming in an acid lake, is no
more dangerous for humans than
walking or swimming in clean water.
However, breathing air that contains the
pollutants that cause acid rain can
damage human health. Sulfur dioxide
(S02), nitrogen oxides (NOX), paniculate
matter, and ozone all irritate or even
damage our lungs. These effects are
mostly seen in people whose lungs have
already been weakened by RESPIRATORY
ILLNESS, but even healthy people can
sometimes have pain or difficulty
breathing because of air pollution.
Ozone is a dangerous pollutant that is
caused by air pollution, especially in the
summer. Exposure to high levels of
ozone have been linked to a number of
health problems. Ozone can make
respiratory illnesses, such as asthma,
emphysema, and bronchitis worse.
Ozone can also reduce the RESPIRATORY
SYSTEM'S ability to fight off bacterial
infections. Even healthy people can have
symptoms related to ozone exposure,
including coughing, pain with deep
breathing, chest tightness, and short-
ness of breath. Over time, ozone can
cause permanent damage to the lungs
or even death. Small particles called
paniculate matter are made up of the
same pollutants that cause acid rain.
Particulate matter also damages the
lungs. The tiny particles of dust that
make up paniculate matter can bypass
the body's natural defenses and become
lodged deep in the lungs, where it can
cause irritation and damage the lungs.
S02 and NOX, the pollutants that cause
acid rain, can also reduce visibility,
limiting how far into the distance we can
see. These pollutants form small parti-
cles in the atmosphere. These particles
reduce visibility by scattering light.
Reduced visibility is most noticeable in
places like National Parks, where people
go to see some of the nation's most
beautiful landscapes.
12
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Effects Of Acid Rain
On Man-Made Materials
Acid rain eats away at stone, metal,
paint—almost any material exposed to
the weather for a long period of time.
Human-made materials gradually
deteriorate even when exposed to
unpolluted rain, but acid rain speeds up
the process. Acid rain can rust metals
and cause marble statues carved long
ago to lose their features. This happens
because marble is made of a compound
called calcium carbonate, which can be
How Acid Rain Affects Metal
dissolved by acids. Calcium carbonate
is also found in limestone. Many build-
ings and monuments are made of
marble and limestone and are damaged
by acid rain. Repairing acid rain damage
to buildings and monuments can cost
billions of dollars. Historical monuments
and buildings, such as the Lincoln
Memorial in Washington, D.C., can
never be replaced.
How Acid Rain Affects
Stonework
The Lincoln Memorial in Washington, D.C.
The picture on the top was taken
in 7908. The picture on the
bottom was taken in 7968.
13
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The Rockport Power Plant in
Rockport, Indiana, burns coal
to produce electricity.
TERMINOLOGY
Cap and Trade An environmental
policy tool that controls large
amounts of emissions from a
group of sources. Cap and trade
programs set a cap, or limit, on
emissions. Then allowances for
emissions are traded between
sources, so that economic market
forces allow large emissions
reductions to be cost-effective.
Cap A national limit that is placed
on the amount of a pollutant
that can be emitted. The cap
is very important because it
makes sure that emissions of
a pollutant are reduced.
What Is Being Done
EPA has been working with Congress and
other federal government agencies;
state, local, and tribal governments;
scientists; and citizens to solve the acid
rain problem for over 15 years.
The Add Rain
Program
The Acid Rain Program was established
by Congress as part of the 1990 Clean Air
Act Amendments. It requires the electric
power industry to lower emissions of
sulfur dioxide (S02) and nitrogen oxides
(NOX), the pollutants that cause acid rain.
By the year 2010, power plants must
reduce emissions of these pollutants by
about 50 percent from levels in 1980.
Today, power plants emit 35 percent less
S02 and 46 percent less NOX than they did
in 1990.
The Acid Rain Program is so successful
because it uses a CAP AND TRADE
program to reduce emissions. A cap and
trade program is a policy that controls
large amounts of emissions from a
group of sources. The approach first sets
an overall CAP, or maximum amount of
emissions allowed, for all pollution
sources under the program. The cap is
chosen in order to meet an
Cap and Trade
Initial Emissions
Total = 30 tons
Allowable Limit (Cap)
-•==•-• Cap Total = 1 5 tons
Plant A
Reduction: 5 tons
Plant B
Reduction: 7 tons
Plant C
Reduction: 3 tons
All three plants were required to reduce their emissions from w tons to 5 tons each. Plant A
reduced its emissions by 5 tons to meet the cap and be in compliance. Plant B reduced its
emissions to 3 tons, 2 tons more than were required. Plant C only reduced its emissions to
7 tons. This is not enough to cover its allowances and be in compliance. In a cap and trade
program, Plant B can sell its two extra allowances to Plant C. Plant C can then use the two
allowances it bought to cover its emissions and stay under its cap.
Notice that even though a trade took place, overall emissions for Plants A, B, and C are within
the cap (5 + 3 + 7 = 15). Total emissions in this cap and trade system are ba\] of what they
used to be (30 tons vs. 75 tons).
14
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environmental goal. In this case the cap
is the maximum level of S02 and NOX
emissions that all power plants
combined can emit. ALLOWANCES, or
permits to pollute a specific amount, are
then given to power plants. It is up to
the individual power plants to decide
how they want to lower their emissions,
but the total amount of emissions from
all power plants across the country must
be less than the cap. If one source
reduces their emissions far below the
amount assigned to them, they are
allowed to sell their leftover emission
allowances to another power plant that
did not reduce their emissions enough.
The option of selling extra emission
allowances to make money is an incen-
tive for the power plants to reduce their
emissions even more than required.
Companies that do not reduce their
emissions enough and emit more
pollution than they have allowances for,
must buy allowances to cover their
emissions or face heavy fines and other
strict penalties. This rarely happens in
the Acid Rain Program because the strict
penalties discourage power plants from
not having enough allowances. In fact,
in 2006, the Acid Rain Program had
TOO percent compliance from sources
of emissions.
Power plants can reduce the amount of
pollution they produce in several ways.
Some plants choose to wash the sulfur
out of coal before it is burned. There are
also different kinds of coal and some
have less sulfur and nitrogen in them.
Pollutants can also be removed from the
smoke as it travels through the smoke-
stack. A device called a SCRUBBER
removes sulfur from the smoke by
spraying a mixture of water and
powdered limestone into the smoke-
stack. This mixture traps the sulfur
before it can escape into the air above.
There are also several other ways to
decrease the pollution coming from
power plants and scientists and engi-
neers are always discovering new ones.
TERMINOLOGY
Allowance The permission, given
by the government, to emit a
certain amount of sulfur dioxide
(S02) or nitrogen oxide (NOX).
Scrubber A device that removes
air pollution, mainly sulfur
dioxi
Je, fr
am s
noke
stack
s.
Wet Acid Deposition, 1989-1991
Wet Acid Deposition, 2003-2005
Source: CASTNET
These maps show how the Acid Rain Program has reduced the amount of wet acid deposition (acid rain) in the United States.
In these maps, the dark areas represent places with high amounts of acid rain. Notice how the areas with lots of acid rain in
7989-7997 have shrunk since the Acid Rain Program started.
15
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TERMINOLOGY
Atmospheric Relating to the
atmosphere, or the air above
the Earth.
Meteorological Pertaining to
the weather.
A CASTNET
Monitoring Site
Cap and trade is most effective when the
environmental or public health issue
occurs over a large area, when there are
many sources of pollution which contrib-
ute to the problem, when emissions can
be monitored, and when there is variety
in the amount of money that sources
must pay to reduce their emissions.
A mandatory cap on emissions is critical
to protect public health and the environ-
ment. The Acid Rain Program and the
NOX Budget Trading Program have been
very effective in reducing emissions of
S02 and NOX. Though long-term environ-
mental monitoring has proven that these
programs are working, studies have
shown that more reductions in emis-
sions are necessary to protect human
health and the environment. In 2009, a
new program called the Clean Air
Interstate Rule (CAIR) will begin. This
program will lower power plant
CASTNET Monitoring Stations
emissions of S02 and NOX in the eastern
United States even further than the Acid
Rain Program.
To learn more about cap and trade, go to
the Clean Air Markets cap and trade Web
site at www.epa.gov/airmarkets/cap-trade/.
If you want to know more about the other
cap and trade programs, like the NOX
Budget Trading program or CAIR, go to the
Clean Air Markets program Web site at
www.epa.gov/airmarkets.
Monitoring
How does EPA know its programs are
working? Experts from EPA, states,
universities, and other agencies have set
up air quality and deposition monitoring
stations across the country. These
monitoring stations contain equipment
that constantly collects air quality data
and samples. These devices measure
many things, including the amount of
pollution in the air, the pH of rain, the
amount of rainfall, and the surrounding
temperature. There are several networks
made up of many stations taking
samples in different areas. The Clean Air
Status and Trends Network (CASTNET)
takes samples from mostly rural areas
around the United States. CASTNET
measures dry deposition and collects
ATMOSPHERIC data. The National
Atmospheric Deposition Program (NADP)
has sites around the United States and
focuses on precipitation and
METEOROLOGICAL monitoring. By using
this information, EPA is able to track the
success of the Acid Rain Program and
other cap and trade programs by linking
CASTNET now has over 80 monitoring stations across the United States.
16
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reductions in emissions to improvements
in air quality. You can see these monitor-
ing stations and the information they
collect online at http://camddataandmaps
.epa.gov/gdm/.
EPA also requires power plants to use
Continuous Emissions Monitoring
Systems (CEMS) to keep track of the
amount of pollution they release into
the air. A CEMS is a monitoring device
that each unit must place on their
smokestack. These monitors take
samples of the air traveling through the
smokestack, and measure the amount of
pollutants traveling through it. Then, the
monitor sends the recordings to EPA.
CEMS allows EPA to keep track of
emissions to make sure that the power
companies are following the laws to
reduce pollution.
Alternative Ways Of
Producing Energy
There are other sources of energy
besides fossil fuels. These include
HYDROELECTRIC POWER, WIND POWER,
NUCLEAR POWER, SOLAR POWER, and FUEL
CELLS. Hydroelectric dams use the power
of water to turn TURBINES and make
electricity. Windmills work the same way
but instead, use wind to turn the
turbines. People have been using wind
and water power for centuries. Nuclear
power plants collect the energy released
by splitting tiny atoms apart inside
nuclear reactors. Although nuclear power
plants generate dangerous waste that
must be disposed of carefully, a small
amount of nuclear fuel can make a very
large amount of electricity. Some people
also use solar power, or power from the
sun, to make electricity. Some houses
use solar power to heat water for
showers, and even some traffic signs
run off of solar panels. Fuel cells are
similar to batteries, except that fuel cells
run on oxygen and hydrogen. They use
chemical reactions to generate electric-
ity, and produce water as a waste.
All sources of energy have benefits and
limitations, including the cost of produc-
ing the energy. All of these factors must
be weighed when deciding which energy
source to use.
Solar Power: Solar panels
produce electricity.
TERMINOLOGY
Hydroelectric Power Energy that
is generated by dams, which
use water to turn turbines
and generate electricity.
Wind Power Energy that is
generated when the wind
turns the sails of a windmill,
which are attached to turbines
that generate electricity.
Nuclear Power Energy that
comes from breaking apart the
center (nucleus) of an atom.
Solar Power Electricity that
is generated by harnessing
the energy of the sun. Solar
panels are often used to
convert sunlight into energy.
Fuel Cells Similar to batteries,
fuel cells store energy that can be
used to power all sorts of things.
Unlike a battery though, fuel cells
do not "run out" and do not need
to be recharged or replaced.
Turbine A motor activated by water,
steam, or air to produce energy.
Wind Power: Windmills produce electricity.
17
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What You Can Do To Help
All environmental problems, including
acid rain, are caused or impacted by the
combined actions of individual people.
This is why individuals can play a big
part in solving these problems. While you
cannot run a nationwide cap and trade
program from your classroom, there are
many things you can do to help reduce
pollution and protect the environment.
To Prevent Acid Rain
»
1. Conserve electricity by turning off
lights, appliances, and computers when
no one is using them.
2. Join ENERGY STAR®'s "Change a Light,
Change the World" program and pledge
to use energy-efficient light bulbs in
your home. This will reduce the amount
of energy you use, and in turn reduce
the amount of emissions produced by
power plants. You can also lower your
energy consumption by using other
Energy Star® products and appliances,
including TVs, computers, refrigerators,
washing machines, air conditioners,
furnaces, etc. For more information,
see EPA's Energy Star® Web site
www.energystar.gov.
3. You can greatly reduce acid rain-caus-
ing emissions (especially NOX emissions)
by changing your transportation habits.
Try to reduce the amount of time you
spend in the car by walking, biking, or
taking public transportation. When you
drive, plan trips ahead of time to
minimize miles traveled, drive the most
fuel-efficient car you can, and carpool
whenever possible. The EPA publishes a
green vehicle guide at www.epa.gov
/greenvehicles/.
4. Shrink your "carbon footprint" and
reduce greenhouse gas emissions by
turning the thermostat down a little bit in
winter, or up a little bit in the summer.
New technologies can also greatly
increase the efficiency of your heating
and air conditioning and other
appliances. Look for the ENERGY STAR®
Label. EPA provides information about
some of these technologies and other
ways to reduce greenhouse gas emissions
at www.epa.gov/climatechange/wycd.
Taking public transportation can help reduce acid rain-causing emissions.
18
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To Address Other
Environmental
Problems
1. Volunteer to help clean up trash and
litter in local streams and rivers, or help
restore wetlands. By cleaning up trash,
you help protect ecosystems that are
important habitats to wildlife. Information
about wetland restoration efforts in your
area can be found in the restoration
project directory at www.epa.gov/owow
/wetlands/restore/.
2. Recycle everything you can at home
and if your school does not already have
a recycling program, start one! This
reduces the amount of waste that you
produce, and keeps recyclable materials
out of landfills. Also, try to buy products
with less packaging, or products with
recyclable packaging. More information
about recycling and waste reduction
programs can be found at EPA's solid
waste education Web site, www.epa.gov
/epaoswer/education.
3. Many areas of the United States,
especially the Southwest, have problems
with water availability. Conserving water
helps ecosystems and the people and
animals that live in them. You can help
by reducing the amount of water you
use by taking shorter showers, or
turning off the faucet while brushing
your teeth. Learn more by visiting the
EPA's Water Sense page at www.epa.gov
/owm/water-efficiency.
Recycling at home is a great way to keep recyclable materials out of landfills.
4. Try talking to your school's principal
or superintendent about ways to reduce
the impacts your school has on the
environment. There are many small
things your school can do to help
protect ecosystems. For some ideas,
check out http://cfpub.epa.gov/schools.
5. Spread the word! Share what you
have learned about Acid Rain and other
environmental problems with others. Tell
them what they can do to protect the
environment. The more information
people have, the more they can do to
make the Earth a cleaner, healthier place.
19
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Experiments
pH Paper
TERMINOLOGY
Litmus Paper Paper coated with a
chemical coloring obtained from
lichens that turns red in acidic
water and blue in basic water. It
is used as an acid-base indicator.
pH Paper Paper that changes color
to show the pH of a substance.
The answers to all of the questions in
the experiments section can be found
at the end of the section, on page 33.
Measuring With
pH Paper
For most of the following experiments,
you will need a pH indicator. A pH indi-
cator contains a chemical that changes
color when it is exposed to acids or
bases. For example, LITMUS and pH
PAPER turn red in strong acids and blue
in strong bases. Because only a few
pH indicators measure pH over a wide
range of pH values, you will need to find
out the pH range of the indicator you
use. Typically, the color chart provided
with each pH indicator kit will show
the pH range of that indicator. Color pH
indicators provide only an approximate
measure of the pH, or the strength
of the acid or base. They are not as
accurate as pH meters, but they are
adequate for the following experiments.
When measuring pH with pH paper or
litmus paper, dip the end of a strip of
the paper into each mixture you want
to test. Follow the directions on the
package regarding how long you need
to keep the pH paper in the mixture
and how long to wait before reading
the measurement. Then compare the
color at the wet end of the paper with
the color chart provided with that pH
indicator. Write down the pH value and
color. Always use a clean, unused strip
of pH paper for each mixture that you
test. Be sure to conduct the pH test for
each substance three times, using a
new pH paper for each test. Record the
results of each test. If possible, have
a different student conduct and record
each test. This helps to ensure scientific
accuracy, consistency, and replicability.
Measuring With
pH Meters
A pH meter provides a more precise pH
measurement than pH paper. Before
using a pH meter, rinse the electrode
with distilled water and blot dry with a
clean paper towel. Calibrate the meter
according to the directions. When testing
the pH of a substance, put the electrode
tip in the mixture and stir once. Be sure
not to touch the bottom or sides of the
container. Hold the electrode in the
mixture for i minute or until the reading
is steady. Record the measurement and
repeat the test two more times for
accuracy and consistency.
20
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For more information on measuring
the pH of soil and water, check out
the pH protocols defined by GLOBE
(Global Learning and Observations
to Benefit the Environment) at
www.globe.gov/protocols.
Tips
• Except for wide-range pH test paper
and pH meters, all the materials called
for in these experiments can be
obtained at grocery stores or from local
lawn and garden stores or nurseries.
• Wide-range pH test paper is pH paper
that covers the whole pH scale. Not all
pH test papers do this. Other papers
cover only part of the pH scale and
there are different papers to test for
acids, bases, and neutrals. Both kinds
are inexpensive, and a school science
laboratory will probably have one or
the other, if not both. If the school
does not already have pH test paper a
science teacher may know where to
order it, or you may order it on your
own through a biological supply
company. If you have to order pH test
paper, we recommend wide range pH
test paper since it can be used for all
the experiments, and may be less
confusing to younger students.
• Baking soda and ammonia are both
bases. You may substitute baking soda
for household ammonia in the experi-
ments. If you do, be sure to stir well
because baking soda does not dissolve
easily in water unless heated. The pH
of undissolved baking soda will not be
the same as dissolved baking soda.
Lemon juice and white vinegar are both
acids. You may substitute fresh-
squeezed lemon juice for white vinegar.
Lemon juice is slightly more acidic than
the vinegar sold in grocery stores. White
vinegar is preferred over cider vinegar
or lemon juice because it is colorless
and relatively free of impurities.
Use clean, dry containers and utensils.
Safety In The
Laboratory
A science or chemistry laboratory can
and should be a safe place to perform
experiments. Accidents can be prevented
if you think about what you are doing at
all times, use good judgment, observe
safety rules, and follow directions.
Always wear protective safety glasses or goggles when working on experiments.
21
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Writing down your observations
can be very helpful.
• Eye protection (goggles or safety
glasses) must be worn when working
on experiments. Make a habit of
putting them on before the experiment
begins and keeping them on until all
clean up is finished.
• Do not eat or drink while in the
laboratory.
• Do not taste any chemical.
• Long-sleeved shirts and closed-toe,
leather-topped shoes must be worn at
all times.
• Long hair must be tied back, so it will
not fall into chemicals or flames.
• Do not work alone; work with an adult.
• Never perform any unauthorized
experiment.
' All glassware must be washed and
cleaned. Wipe all counter surfaces and
hands with soap and water.
• All experiments that produce or use
chemicals must be done in a well-
ventilated area.
• Never point the open end of a test
tube at yourself or another person.
> If you want to smell a substance, do
not hold it directly to your nose.
Instead, hold the container a few
centimeters away and use your hand
to fan vapors toward you.
1 When diluting acids, always add the
acid to the water; never water to acid.
Add the acid slowly.
• Dispose of all chemicals properly,
according to the directions of your
teacher.
• If you spill any acid or base material
on you, wash the exposed area with
large amounts of cold water. If skin
becomes irritated, see a physician.
Recording
Observations
Writing your observations on these
experiments will help you to keep
better track of the progress of the
experiment and help you to remember
information for answering questions or
writing lab reports. Record keeping can
be very simple and still be a help. These
hints can help you organize and record
your thoughts.
• Use a bound notebook so that pages
are not lost.
• Write complete sentences for all
written entries.
• Use drawings as needed.
• Date each entry (even drawings).
• Use the title of the experiment as your
first entry.
• When your observation entries have
been completed, write your answers
to the questions that follow each
experiment.
• Write your own thoughts about the
experiment as the conclusion.
22
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Experiment O
Measuring pH
Materials
Q pH paper and color chart or
pH meter (pH range 3 to 12)
Q i 72 cups distilled water
Q 1/2 teaspoon white vinegar
Q 1/2 teaspoon household ammonia
Q 3 small cups or beakers
Q 3 clean stirring spoons
Q measuring cups and spoons
(1/2 cup and 1/2 teaspoon)
Q notebook and pencil
Instructions
O Label the first cup "vinegar," the
second cup "ammonia," and the
third cup "water."
© Pour 1/2 cup distilled water into
each of the 3 cups.
€) Add 1/2 teaspoon white vinegar
to the vinegar cup and stir with
a clean spoon.
O Add 1/2 teaspoon ammonia to
the ammonia cup and stir with
a clean spoon.
© Do not add anything to the
water cup.
0 i^&3 which substance do you think
will be an acid? Which one will be a
base? Take a moment to write down
your hypotheses.
Follow the instructions that come
with your pH paper or pH meter for
testing the pH of the vinegar mix-
ture. Record the pH value.
Follow the instructions that come
with your pH paper or pH meter for
testing the pH of the ammonia
mixture. Record the pH value.
Follow the instructions that come
with your pH paper or pH meter for
testing the pH of the distilled water.
Record the pH value.
Repeat steps 7-9 two more times so
you test and record the pH results a
total of three times for each mixture.
Questions
i. Is vinegar an acid or a base?
2. Is ammonia an acid or a base?
3. What is the pH of distilled water?
Did the pH level surprise you? Why
do you think distilled water did not
have a neutral pH?
4. Were your hypotheses correct?
•
This experiment
will illustrate how
to measure the
approximate pH of
chemicals in water
using a pH indicator.
mis experiment will
take approximately
20 minutes
23
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In this experiment,
you will use a pH
indicator to measure
the pH of some fruits,
common beverages,
and soaps. Many
foods and household
cleaners are either
acids or bases.
This experiment will
take approximately
40 minutes
Experiment
Determining The pH Of
Common Substances
Materials
Q pH paper and color chart or
pH meter (range pH 2 to 12)
Q 3 different fresh, whole fruits
(lemon, lime, orange, or melon)
Q 3 different beverages (cola,
carbonated non-cola, milk)
Q 1/8 teaspoon dish soap or
laundry detergent
Q 1/4 cup distilled water
Q measuring cups and spoons
(1/2 cup, 1/4 and 1/8 teaspoon)
Q 4 small cups or beakers
Q i clean stirring spoon
Q notebook and pencil
Q paring knife
Instructions
O Using the knife, carefully cut each
fruit in half, cleaning off the knife
after each cut.
© Label the 3 cups "cola," "non-cola,"
and "milk."
€) Pour about 1/2 cup of each liquid
into the appropriately labeled cup.
O In the fourth cup add 1/8 teaspoon
soap to 1/4 cup distilled water and
stir for about 2 minutes.
© &% Given what you have learned,
which items do you think will be
acids? Which will be bases? Why?
Take a moment to write down your
hypotheses.
Follow the instructions that come
with your pH paper or pH meter for
testing the pH of each fruit. Record
the pH value. Be sure to use a clean,
unused pH paper for each one or
clean the pH meter electrode be-
tween testing each substance.
Follow the instructions that come
with your pH paper or pH meter for
testing the pH of the cola and other
beverages. Record the pH value. Be
sure to use a clean, unused strip of
pH paper for each one or clean the
pH meter electrode between testing
each substance.
Follow the instructions that come
with your pH paper or pH meter for
testing the pH of the soap mixture.
Record the pH value.
Be sure to conduct the pH test three
times for each fruit or substance
and record the results of each test.
Questions
i. Are lemons, limes, oranges, and
melons acids or bases?
2. Are colas and non-colas acids
or bases?
3. Was the milk acidic or basic?
4. Was the soap/detergent mixture
acidic or basic?
5. Which item is most acidic? Which
one is most basic? How can you tell?
6. What other foods or drinks are
acids? Why?
7. Were your hypotheses correct?
24
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Experiment
Making A Natural pH Indicator
Materials
Q i head of red cabbage, sliced
Q stainless steel or enamel pan or
microwaveable casserole dish
i quart water
stove, microwave, or hotplate
1/2 teaspoon white vinegar
1/2 teaspoon ammonia
i teaspoon clear, carbonated
beverage, like seltzer water or
lemon-lime drinks
3 small clear cups or beakers
3 clean stirring spoons
measuring cups and spoons
(i quart, 1/4 cup, 1/2 and
i teaspoon)
notebook and pencil
Instructions
O Boil sliced cabbage in i quart
of water in a covered pan for
30 minutes or microwave for
10 minutes. (Don't let the water
boil away.)
© Let cool before removing the
cabbage.
€) Label 3 cups "ammonia," "vinegar,"
and "beverage."
O Pour about 1/4 cup of cabbage juice
into each cup.
^ What color do you think the
cabbage juice will turn when you
add ammonia? What about when
you add vinegar or the beverage?
Take a moment to write down your
hypotheses.
Add 1/2 teaspoon ammonia to the
cup labeled "ammonia" and stir
with a clean spoon.
Add 1/2 teaspoon vinegar to the cup
labeled "vinegar" and stir with a
clean spoon.
Add i teaspoon clear non-cola to the
last cup and stir with a clean spoon.
Record and observe what happens to
the color of the liquid in each cup.
After answering the first two
questions for this experiment, pour
the contents of the vinegar cup into
the ammonia cup.
•
Questions
i. What color change took place when
you added vinegar to the cabbage
juice? Why?
2. Did the ammonia turn the cabbage
juice pH indicator red or blue? Why?
3. If you were to gradually add vinegar
to the cup containing the ammonia
and cabbage juice, what do you
think would happen to the color
of the indicator? Try it, stirring
constantly.
4. Is the non-cola soft drink acidic
or basic?
5. Were your hypotheses correct?
In this experiment,
you will make your
own pH indicator
from red cabbage.
Red cabbage contains
a chemical that turns
from its natural deep
purple color to red
in acids and blue in
bases. Litmus paper,
another natural pH
indicator, also turns
red in acids and blue
in bases.
mis experiment will
take approximately
50 minutes
25
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In this experiment,
you will measure the
pH of rainwater and
natural water located
near your home or
school.
TERMINOLOGY
Surface Water Water that is found
on the surface of the Earth in
lakes, ponds, streams, or rivers.
This
experiment will
take approximately
15 minutes in the
classroom with
additional time fofs
water collection
Experiment O
Measuring The pH Of Natural Water
Materials
Q pH paper and color chart or
pH meter (range pH 2 to 7)
clean cups or beakers
2 clean, empty, water or soda bottles
notebook and pencil
A map of the pH of rainwater in the
United States, which can be found at
http://nadp.sws.uiuc.edu/isopleths.
After clicking on annual maps and
selecting the most recent year
available, select the report titled
"Lab pH."
Instructions
O Label a clean, empty water or soda
bottle "rainwater," and leave it
outside of your classroom to collect
water on a rainy day.
© After you have collected at least a
tablespoon of water, cap the bottle to
prevent evaporation and bring it
inside.
€) Locate a local stream, river, lake, or
pond. Go with an adult. Depending
on where you live, you may choose
to gather water samples from many
sources, including different creeks,
lakes, ditches, ponds, and rivers.
O Scoop some of the SURFACE WATER
into a clean, empty water or soda
bottle. Label the bottle "surface
water," and cap the bottle to
prevent evaporation and spilling
while you bring it home.
Do you think the rainwater you
collected will be acidic? What about
the different surface water samples?
Why? Take a moment to write down
your hypotheses.
Pour the rain water into a cup and
measure the pH of the rainwater
using pH paper or a pH meter and
record the result.
Pour the surface water into a cup
and measure the pH of the surface
water using pH paper or a pH meter
and record the result.
Repeat steps 6 and 7 two more
times so you test and record the pH
results a total of three times for
each sample.
Questions
i. What is the pH of the rainwater?
Compare your results to the map.
Is it what you expected?
2. What is the pH of the surface water?
3. How does the measured pH compare
to the pH levels that affect plants
and animals in aquatic habitats?
(See chart on page n.)
4. Was one of your samples more
acidic than the other? Which one? If
they are different, what do you think
the reason for the difference is?
5. Were your hypotheses correct?
26
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Experiment
Measuring Soil pH
Materials
Q garden soil pH test kit
Q 2 cups soil from each of two or
three different locations (some of
the soil will be needed for the "Soil
Buffering" experiment)
Q measuring spoons
Q digging tool
Q self-sealing plastic bags
Q notebook and pencil
Instructions
O Pick two or three different soil
locations, such as a garden, the
school grounds, a wooded area, city
park, meadow, etc. Go with an adult.
© At each location, quietly observe the
plants and animals living in or
rooted on these soils, especially
those that are in greatest numbers.
Write down your observations.
€) Dig down about 2 inches, scoop out
2 cups of soil, and seal it in a plastic
bag for later use. Be sure to clean
your digging tool after collecting soil
samples at each location.
O Label each plastic bag.
0 ^D what do you think the pH level
of the soil from each location will
be? Why? Take a moment to write
down your hypotheses.
Back in the classroom, measure the
pH of each soil sample following the
directions provided in the garden
soil pH test kit, and record the
approximate pH of each soil sample.
Save the excess soil from each site
for use in the "Soil Buffering"
experiment.
Questions
i. What were the differences between
the plant and animal life at each
location?
2. What was the range of pH levels at
various sites?
3. Were any of your soil samples acidic?
4. Were any of your soil samples basic?
5. Name some possible reasons for the
different pH levels at the sites.
6. How do your plant and animal
observations at each location and
the pH level of the soil compare to
the chart on page n?
7. Were your hypotheses correct?
In this experiment,
you will collect soil
and measure its pH.
Soil pH is one of
several important
conditions that
affect the health of
plants and animals.
In addition, you will
also be asked to
survey the plants and
animals that live in
the area where you
collected the soil.
Area surveys provide
information about
how well plants
and animals can
live under different
conditions.
For this experiment,
you will need an
inexpensive garden
soil pH test kit, which
may be obtained from
lawn and garden
stores or nurseries.
This
experiment will
take approximately
20 minutes in the
Iclassroom with additional]
time for soil sample
collection
27
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In this experiment,
you will find out if
soil from your lawn,
garden, or school
can buffer acids. You
will observe the pH
change of an acid
mixture poured over
soil in a filter. If the
water collected from
the filter is less acidic
than the original
mixture, then the soil
is buffering some of
the acid. If it does not
change, then the soil
may not be capable
of buffering acids.
Since the buffering
capability of soils
differs, you may want
to do this experiment
with several different
soil types including
those collected
for Experiment 5,
"Measuring Soil pH".
This
experiment will
take approximately
30-60 minutes
depending on the
number of soil
samples used
Experiment
Soil Buffering
Materials
Q pH paper and color chart or
pH meter (pH range 2 to 10)
Q about 2 cups of soil from a garden,
wooded area, lawn, or school yard
distilled water
white vinegar
ammonia
measuring cups and spoons
0 cup and i teaspoon)
clean stirring spoon
large funnel
coffee filters
clean cups or beakers
notebook and pencil
Instructions
O Pour i teaspoon of vinegar into
i cup of distilled water. Stir well.
© Check the pH with pH paper or a pH
meter. The pH of the vinegar/water
mixture should be about 4. If it is
below that, add ammonia, stir well,
and recheck the pH. If it is above pH
4, add a drop or two of vinegar and
again recheck the pH.
€) Put i coffee filter into the funnel,
and fill the filter with soil from one
location. The soil should be slightly
packed down, so that the water runs
through it slowly. Dense sandy or
clay soils might not need to be
packed down, but this may be
necessary for looser, loamy soils.
O
Hold the funnel over a cup and slowly
pour the vinegar/water mixture over
the soil until some water collects in
the cup. The filter may clog quickly,
but you need only a small amount of
water in the cup to test the pH.
what do you think the pH of the
water will be after it filters through
the soil? Why? Do you think it will
be different for each of the soil
samples? Take a moment to write
down your hypotheses.
Check the pH of the collected water
using pH paper or a pH meter and
record the results.
Repeat step 4 with the other
soil samples, washing the funnel
and using a new coffee filter for
each sample.
Repeat step 6 two more times so you
test and record the pH results a total
of three times for each soil sample.
Questions
i. How did the pH of the collected
water change?
2. Why is it important that soil
buffer acid?
3. What does acid rain do to soil, and
why is this a problem?
4. Were your hypotheses correct?
28
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Experiment®
Observing The Influence Of
Acid Rain On Plant Growth
Materials
Q pH paper and color chart or pH
meter (pH range 2 to 8)
Q 3 of the same type of healthy,
potted plant
Q 3 one-gallon containers with lids
(such as a milk jug), one per group
of three to four students
Q i pint white vinegar
Q tap water with a pH of 7
Q measuring cup (i pint)
Q notebook and pencil
Q poster paper, crayons, markers for
class presentations
Instructions
O Divide the class into three teams.
© Give each group a i-gallon container
(such as a milk container).
© One team will fill their container
with i gallon (3.8 liters) of tap water.
Label the container "tap water."
O Another team will fill their container
with i pint (0.5 liters) of vinegar and
7 pints (3.3 liters) of tap water. Label
the container "slightly acidic."
© The third team will fill their contain-
er with 2 pints (0.9 liters) of vinegar
and 6 pints (2.8 liters) of tap water.
Label the container "very acidic."
© Test the pH of each mixture ("tap
water," "slightly acidic," and "very
acidic") three times and record
each result.
O Each team will receive a potted
plant and label their plant the same
as their container.
© Each team will be responsible for
watering their plant from the
container with the matching label.
Students should water the plants
when they need it (every 2-4 days).
Make sure each group's plant gets
the same amount of water in each
watering cycle. A good way to do
this is to give each group a cup to
use when watering.
© Place all three plants in the same
spot so that they get the same
amount of light.
(5) &% What do you think will happen
to each plant? Will they differ after
a few weeks? In what way? Why?
Take a moment to write down your
hypotheses.
0 Have team members examine
their plants every day and write
their observations. What do the
plants look like? What color are
they? Are the leaves dropping?
Do they look healthy?
© Continue this activity for 2-3
weeks. Then have students
examine the plants and discuss
or give presentations on the
results of the experiment.
Questions
•
i. Do the plants watered with acid
solutions differ in color or size from
the others?
2. How long did it take to see the
effects of each mixture?
3. Which plant showed the most
effects? Why?
4. Were your hypotheses correct?
Acid rain most often
damages plants
by washing away
nutrients and by
poisoning the plants
with toxic metals,
but it can have
direct effects on
plants as well. In
this experiment, you
will observe one of
the direct effects of
acid rainwater on
plant growth. The
experiment will take
2-3 weeks.
This
experiment will
take approximately
20 minutes on day i
15 minutes a day to
record observations,
60-80 minutes for
presentations
29
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When acids and
metals are exposed to
each other, the metal
is gradually dissolved
away in a chemical
reaction. In this
experiment, you will
observe this reaction
for yourself, but you
will need patience.
The chemical effect of
acids on metals may
take at least 5 days
for the human eye
to see, even though
the reaction starts
as soon as the acid
contacts the metal.
This
experiment will
take approximately
20 minutes the first day
and 5-10 minutes each
additional day
Experiment©
Looking At Acid's Effects On Metals
Materials
Q pH paper and color chart or
pH meter (pH range 2 to 7)
Q 2 cups or beakers
Q 2 clean copper pennies (use pennies
minted before 1983)
Q 3 tablespoons white vinegar
Q 3 tablespoons distilled water
Q ammonia
Q measuring spoon (i tablespoon)
Q plastic wrap
Q notebook and pencil
Instructions
O Label one cup "water" and the
other "vinegar".
© Put 3 tablespoons of vinegar into
the cup, enough to cover the
penny completely.
€) Test the pH of the vinegar and
record the result.
O Put 3 tablespoons of distilled water
into the cup, enough to cover the
penny completely.
© Test the pH of the distilled water. If
the pH is below 6, add ammonia and
recheck the pH. Repeat this process
until the pH is between 6 and 7.
Record the pH of the water.
@ Repeat steps 3 and 5 two more
times so you test and record the pH
results a total of three times for
each sample.
-------
Experiment
Observing The Influence Of
Acid Rain On Marble And Limestone
Materials
Q pH paper and color chart or
pH meter (pH range 2 to 7)
Q 2 pieces of chalk
Q 2 cups or beakers
Q plastic wrap
Q 1/4 cup tap water
Q 1/4 cup white vinegar
Q measuring cup (1/4 cup)
Q notebook and pencil
Instructions
O Label one cup "vinegar" and one
cup "water."
© Pour 1/4 cup vinegar into the cup
labeled "vinegar."
© Test the pH of the vinegar and
record it.
O Pour 1/4 cup tap water into the cup
labeled "water."
© Test the pH of the water and record it.
© Repeat steps 3 and 5 two more
times so you test and record the pH
results a total of three times for
each mixture.
O Place one piece of chalk in each cup.
If you need to add a little more
water or vinegar to submerge the
chalk, do so.
© Cover each cup with plastic wrap to
prevent evaporation, and put in a
safe place overnight.
g) ^B what do you think will happen
to the piece of chalk in each
mixture? Why? Take a moment to
write down your hypotheses.
Jt) The next day, observe the two
pieces of chalk and record the
changes that occurred.
•
Questions
i. Which piece of chalk is more worn
away? Why?
'
2. Have you seen any buildings in
your town that show evidence of
acid rain damage? What about the
grave markers at an old cemetery?
Would you consider acid rain a
major problem in your town? Why
or why not?
3. Have you seen acid rain damage
on any buildings or monuments in
other parts of the United States or
other countries? Describe what you
saw and where it was. If you do not
know of any buildings or monu-
ments that have been harmed by
acid rain, go online and try to find
some pictures of some.
4. Were your hypotheses correct?
Acids do not just
eat away at metals.
They also eat away
at rocks like marble,
limestone, and chalk
that are made of
calcium carbonate.
Calcium carbonate
is also found in
seashells, bones, and
teeth. Acids dissolve
hard rocks, like
marble, very slowly.
It can take decades
for acid rain damage
to become evident on
marble structures.
Soft rocks, like chalk,
can be dissolved
much quicker, which
is why we use it in
this experiment. In
this experiment, you
will observe how acid
can dissolve calcium
carbonate.
This experiment will
take approximately
15 minutes
each day
\
31
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V
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Experiment Answers
Below are the answers to the questions
provided at the end of each experiment.
Experiment 1: Measuring pH
i. Vinegar is an acid, and in this experi-
ment, it will display a pH of about 4.
Vinegar at pH 4 turns pH paper yellow
and most other pH indicators red.
2. Ammonia is a base and in this
experiment, it will display a pH of about
12. Bases turn most pH indicators blue.
3. Pure distilled water would have tested
neutral, but pure distilled water is not
easily obtained because carbon dioxide
in the air around us mixes, or dissolves,
in the water, making it somewhat acidic.
The pH of distilled water is between 5.6
and 7. You can neutralize distilled water
by adding about 1/8 teaspoon baking
soda, or a drop of ammonia, and stirring
well. Check the pH of the water with a
pH indicator. If the water is still acidic,
repeat the process until pH 7 is reached.
Should you accidentally add too much
baking soda or ammonia, start over or
add a drop or two of vinegar, stir, and
recheck the pH.
4. Answers will vary.
Experiment 2: Determining The
pH Of Common Substances
i. These fruits all contain acids and taste
sour. Lemons and limes have pH values
near 2. Oranges may be slightly less
acidic than lemons and limes, but your
pH indicator may not be accurate
enough to show the difference.
2. They are both acidic, primarily
because they both contain carbon
dioxide to make them fizz, and carbon
dioxide and water produce carbonic
acid. The pH of these beverages varies
with the amount of carbon dioxide and
other ingredients in them, but it is
usually below 4.
3. Milk can be slightly basic or slightly
acidic depending on its age and how it
was processed at the dairy.
4. Soap contains a base and will turn
most pH indicators blue. Alkaline
solutions are excellent cleaning agents,
which is why we use them to wash
dishes and clothes.
5. Answers will vary. You can tell by
checking their pH.
6. Answers will vary.
7. Answers will vary.
Experiment 3: Making A
Natural pH Indicator
i. The vinegar and cabbage juice mixture
should change from deep purple to red,
indicating that vinegar is an acid.
2. The ammonia and cabbage juice
mixture should change from deep purple
to blue, because ammonia is a base,
which reacts chemically with the pH
indicator, turning it blue.
3. You should find that the acid and
base are neutralized, changing the
color from blue or red to purple, which
is the original, neutral color of the
cabbage juice.
33
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4. The non-cola soft drink is acidic and
turns the cabbage juice pH indicator red.
5. Answers will vary.
Experiment 4: Measuring The
pH Of Natural Water
i. Answers will vary.
2. Answers will vary.
3. Answers will vary. See the chart on
page n explaining how acid rain affects
animals living in the water.
4. The rainwater should be more acidic
than the surface water from the pond or
stream. This is because most surface
water travels through soil and is buff-
ered, or made less acidic, before reach-
ing a pond or stream. It is important to
note that runoff from agricultural areas
containing pesticides or fertilizers or
runoff of industrial pollutants discharged
(legally or illegally) into streams may
affect the results of this experiment.
5. Answers will vary.
Experiment 5: Measuring
SoilpH
i. Some types of plants and animals are
able to live in acid soils, while others
are not. Be aware, however, that many
factors, not just the soil acidity, deter-
mine the types of plants and animals
that occur at a particular site.
2. Answers will vary.
3. Some plants require acid soils to grow
and thrive. For example, pine trees,
azaleas, rhododendrons, cranberries,
blueberries, potatoes, and tomatoes
prefer acid soils. However, most plants
thrive only in soils of pH 6 to 7.
4. Some soils, such as in many
Midwestern states, contain a lot of
limestone and are alkaline. In those
locations, people often add sulfate, such
as ammonium bisulfate to soil to make
it less basic.
5. Answers will vary, depending on
where the soil samples came from. The
underlying rock can have a large effect
on soil pH, and so can industrial or
agricultural runoff in the area.
6. Answers will vary.
7. Answers will vary.
Experiment 6: Soil Buffering
i. If the pH stayed the same, the soil did
not buffer the acid. Each pH value above
4 indicates that the soil buffered increas-
ing amounts of the acid.
2. Not all plants and animals can live in
acidic soil, so by buffering the acid the
soil makes the environment more
habitable.
3. Even soil capable of buffering acids
can be overpowered if enough acid is
added. As more acid is added to the soil
by acid rain, the buffering capability
decreases, and the soil becomes more
acidic. This can hurt delicate ecosystems
like forests.
4. Answers will vary.
34
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Experiment 7: Observing The
Influence Of Acid Rain On
Plant Growth
i. The plants watered with acidic
solutions will not do as well as the
plants watered with clean water. Some
effects of the acidic solution on plant
growth are withering or drooping leaves,
change in leaf color, and stunted growth.
2. The effects of the very strong acidic
solution on the plants should be visible
within a few days. The less acidic
solution may not affect the plant for a
week to a week and a half. The degree
to which the plant is affected by the
acid depends on the health of the plant
and the hardiness of the species.
3. The plant watered with the very acidic
solution should exhibit significantly
more damage than the plant watered
with the weaker acidic solution.
4. Answers will vary.
Experiment 8: Looking At
Acid's Effects On Metals
i. There should be no change.
2. The liquid should be bluish-green. The
bluish-green substance in the vinegar
comes from the copper in the penny. It
is a byproduct of the chemical reaction
in which the acid in the vinegar gradu-
ally eats away the penny.
3. The chemical reaction between the
acid and the copper penny is so slow
that you cannot see any difference in
the shape of the metal in just 5 days, at
least not with your eye alone. You may
see some changes after about 2 weeks,
especially at the edge of the penny.
4. Answers will vary.
Experiment 9: Observing The
Influence Of Acid Rain On
Marble And Limestone
i. The chalk in the vinegar should be
significantly more worn away then the
piece of chalk in the distilled water. This
is because the acid dissolves the
calcium carbonate in the chalk.
2. Answers will vary.
3. Answers will vary.
4. Answers will vary.
35
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A J.' 'A'
Activities
Join GLOBE (Global Learning and
Observations to Benefit the
Environment) at www.globe.gov.
Collect data on the pH of rain,
surface water, and soil according to
GLOBE'S protocols and post your
results on GLOBE'S online database.
Compare your results to other
student's results in the United
States and around the world.
Role play different characters involved
in or affected by acid rain. Each
person in the class takes the role of
an interested party (for example a
fish, bird, coal miner, farmer, factory
owner, power company, stream, lake,
tree, etc.). With each student or
group playing a character, have a
group discussion or debate on acid
rain. Tell the rest of the class how
acid rain affects your character, and
then present an argument for or
against laws that control acid rain.
As individuals, contact your local
power company. If you have a large
class, you may also want to assign
some students to research power
companies from other parts of the
country. Many power companies use
more than one source of power to
make enough electricity for the
community. Some also buy electricity
from other power companies. Ask
the power company what sources of
energy it uses (hydroelectric, nucle-
ar, gas, oil, coal, other) and what
percentage of their energy output
comes from each source. Write down
results to report to the class.
In small groups or as individuals,
write, produce, and direct a special
segment for a TV weather special
on the effect of weather patterns on
the travel of air pollution over large
distances. Contact the weather bu-
reau or a local TV station's weather
department to ask about the wind
patterns in your area. Use the EPA
Clean Air Market Division's data and
maps Web site (http://camddata
andmaps.epa.gov/gdm/) to find
power plants and their emissions in
your area. The EPA's C-MAP Web site
(www.epa.gov/airmarkets/maps
/c-map.html) is another online tool
that you can use to perform this
activity. Map where you think pol-
lution from local power plants may
end up. Discuss what communities,
cities, ecosystems, parks, schools,
etc. may be affected.
ac'd rain fects of
This power plant in Tennessee uses hydroelectric energy to produce electricity.
37
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Contact your local water
company to find out where
your water comes from.
Learn how EPA regulates the
emissions that cause acid rain. EPA
has several programs that control
emissions. Research the Acid Rain
Program, NOX State Implementation
Plan (SIP) Call, NOX Budget Trading
Program, or the Clean Air Interstate
Rule (www.epa.gov/airmarkets).
Write a report on what pollutants
these programs regulate and how
they regulate them.
Invite a local natural resource
specialist from a zoo, aquarium,
nature center, or national/state park
to come in and speak to your class
about the effects of acid rain on
animals and their habitat. You could
also telephone natural resource
specialists around the country.
Interview the specialist and ask
them to tell you about the impact of
acid rain and dry deposition on the
lakes, forests, or other natural
resources in your area. Write down
what you have learned in a report.
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Contact a local natural resource specialist and have them come in to speak about
the effects of acid rain on animals and their habitat.
EPA has regional offices around the
nation. Contact your regional EPA
office, and ask a representative from
EPA to visit your class. Prepare for
their visit by brainstorming interview
questions to ask them when they
visit. You may want to ask them
about the effects of acid rain in your
region of the country, or what other
environmental issues they believe
are most pressing in your region.
When they come to class, take turns
asking questions, and write a
newspaper article about the inter-
view. The locations of EPA regional
offices and contact information can
be found online at www.epa.gov
/epahome/locatea.htm.
Call or visit your local water com-
pany. Ask them where your water
comes from: a well, lake, reservoir, or
river. If you have a private well, ask
your parents if the water is treated
for acidity, and if so, how. When
talking to the water company, ask
how they treat the water for acidity.
Ask if they can tell you the pH of the
water before it is treated, and after it
is treated. Is it completely neutral-
ized? Write down their answers in a
report to give to the class.
Contact a local architecture firm,
an architecture department at a
local university, a member of a state
or national Green Building Council,
or the EPA ENERGY STAR® program,
and see if you can get someone to
visit your classroom and describe
how homes, schools, and office
buildings can use energy and
resources more efficiently.
38
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Games
Crossword Puzzle
DIRECTIONS
Read each clue below then find the
number in the puzzle that corresponds
to each clue. To assist you, there is a list
of possible answers to each clue below
the puzzle. Now it is time to see how
many clues you can get correct!
ACROSS
3. A solution is
when it has
a pH higher than 7.0.
5. When power plants burn
they release sulfur dioxide and
nitrogen oxides into the air.
7. Wet
fog, and snow.
refers to acidic rain,
deposition can be wet
11. You can acidic water by
or dry.
adding a base.
13. A
removes sulfur dioxide
from the gases leaving the smoke-
stack of a power plant.
DOWN
i. The government gives an
to a power plant, letting it release a
set amount of sulfur dioxide.
2. One way that people can help
prevent acid rain is by joining a
, in which individuals
share rides to their destination and
reduce the number of cars polluting
the air.
. is to turn from gas or
vapor into liquid form.
6. An
. consists of plants
and animals and the environment in
which they live.
8. Sulfur dioxide, nitrogen oxides,
ozone, and paniculate matter are
examples of .
10. Hydroelectricity is produced from
the energy of running .
12. Solar energy is energy that comes
from the _ .
POSSIBLE ANSWERS
Add
Allowance
Basic
Carpool
Coal
Condense
Deposition
Ecosystem
Neutralize
Pollutants
Scrubber
Sun
Water
39
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Word Search
DIRECTIONS
All words that are listed below are hidden in the collections of scrambled letters.
Your goal as an acid rain detective is to find as many words as possible. Look very
carefully - the words can go forwards, backwards, up and down, and diagonally.
How good are your detective skills?
FIND WORDS
Acidic
Allowance
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Buffer
Cap
Carpool
Chemical
Coal
Deposition
Ecosystem
Emissions
Geothermal
Hydropower
Pollution
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Game Answers
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41
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Additional Resources
Readings
Parks, Peggy J. Acid Rain (Our
Environment Series). Detroit [Ml]:
KidHaven Press, 2006. Ages 12 and up.
Petheram, Louise. Acid Rain. Mankato
[MM]: Capstone Press, 2002. Ages 8 to 9.
O'Connor, Rebecca K. Acid Rain (Lucent
Overview Series). Farmington Hills [Ml]:
Lucent Books, 2003. Ages 12 and up.
Allaby, Michael. Fog, Smog, and Poisoned
Rain (Facts on File Dangerous Weather
Series). New York [NY]: Facts on File, May
2003. Ages n and up.
Johnson, Rebecca L. Acids and Bases
(Physical Science Series). New York:
National Geographic, 2004. Ages 9
through 13.
Web sites
EPA has information on acid rain and
other air quality issues at www.epa.gov
/airmarkets/index.html.
Find resources and activities on EPA's
general site for teachers and students
at www.epa.gov/regions/teachers.
The EPA's Acid Rain for Kids site can be
accessed at www.epa.gov/acidrain
/education/site_kids.
The Acid Rain Program Annual Reports are
available online at www.epa.gov/airmarkets
/progress/progress-reports.html.
The U.S. Geological Survey Web site has
an acid rain page at http://ga.water.usgs
.gov/edu/acidrain.html.
The National Park Service has a great
students and teachers Web site at http://
www2.nature.nps.gov/air/edu/index.cfm.
The Geological Society of America has
information on several environmental
issues at www.geosociety.org /educate
/LessonPlans/i_water.htm.
The National Atmospheric Deposition
Program site has some more information
for teachers or older students, including
links to data and maps at http://nadp
.sws.uiuc.edu/. It also has a page that
links to several good online resources
for all ages at http://nadp.sws.uiuc.edu
/cal/Educational_lnformation.htm.
The National Oceanic and
Atmospheric Administration has a
students and teachers resource page at
http://oceanservice.noaa.gov/kids.
You can look at acid rain data collected by
students around the world, or even
upload your own on the GLOBE Web site
at www.globe.gov/fsl/welcome.html.
Audiovisuals
Acid Rain (DVD) Educational Video
Network, Inc., 2004. Run Time:
20 minutes.
Air Pollution, Smog, and Acid Rain (DVD)
Educational Video Network, Inc., 2004.
Run Time: 21 minutes.
42
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Glossary
Acid Any of a large group of chemicals
with a pH less than 7. Examples are
battery acid, lemon juice, and vinegar.
Acidic Describes a substance with a pH
less than 7.
Acid Deposition Acidic material that falls
from the atmosphere to the Earth in
either wet (rain, sleet, snow, fog) or dry
(gases, particles) forms.
Acid Rain Rain that has become acidic
by contact with air pollution. Other
forms of precipitation, such as snow and
fog, are also often included in the term
acid rain or acid wet deposition.
Allowance The permission, given by the
government, to emit a certain amount
of sulfur dioxide (S02) or nitrogen
oxide (NOX).
Aluminum A silvery-white metal; it is
the most abundant metal in the
Earth's crust.
Aquatic Relating to water.
Atmosphere The air or gases that
surround a planetary body such as
the Earth.
Atmospheric Relating to the atmosphere,
or the air above the Earth.
Base Any of a large group of chemicals
with a pH greater than 7. Examples are
ammonia and baking soda.
Basic Describes a substance with a pH
greater than 7. Another word for basic
is alkaline.
Buffer A substance, such as soil,
bedrock, or water, capable of
neutralizing either acids or bases.
Buffering Capacity The ability of a
substance to resist changes in pH when
acids or bases are added.
Cap A national limit that is placed on
the amount of a pollutant that can be
emitted. The cap is very important
because it makes sure that emissions of
a pollutant are reduced.
Cap and Trade An environmental policy
tool that controls large amounts of
emissions from a group of sources. Cap
and trade programs set a cap, or limit,
on emissions. Then allowances for
emissions are traded between sources,
so that economic market forces allow
large emissions reductions to be cost-
effective.
Carbon Dioxide (C02) A naturally
occurring gas made carbon and oxygen.
Sources of carbon dioxide in the
atmosphere include animals, which
exhale carbon dioxide, and the burning
of fossil fuels and biomass.
Condense To change from gas or vapor
to liquid form.
Deposition When chemicals like acids or
bases fall to the Earth's surface.
Deposition can be wet (rain, sleet, snow,
fog) or dry (gases, particles).
Dry Deposition The falling of small
particles and gases to the Earth without
rain or snow.
43
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Ecology The study of ecosystems.
Someone who studies ecology is called
an ecologist.
Ecosystem All the living and nonliving
things in an area, as well as the
interactions between them.
Emissions The gases that are released
when fossil fuels are burned.
Energy Resources Natural resources that
can be used to make heat, electricity, or
any other form of energy. The most
commonly used energy resources are
fossil fuels (coal, oil, and gas), but the
sun, wind, and anything else that makes
energy are also energy resources.
Environment The air, water, soil,
minerals, organisms, and all other
factors surrounding and affecting an
organism.
Evaporate To change from liquid
into gas.
Fossil Fuels Oil, natural gas, and coal.
Fossil fuels were made in nature from
ancient plants and animals, and today
we burn them to make energy.
Fuel Cells Similar to batteries, fuel
cells store energy that can be used to
power all sorts of things. Unlike a
battery though, fuel cells do not "run
out" and do not need to be recharged
or replaced.
Greenhouse Gases Gases that occur
naturally in the Earth's atmosphere and
trap heat to keep the planet warm.
Some examples are carbon dioxide,
water vapor, halogenated fluorocarbons,
methane, hydrofluorocarbons, nitrous
oxide, perfluoronated carbons, and
ozone. Some human actions, like the
burning of fossil fuels, also produce
greenhouse gases.
Habitat The place where a plant or
animal lives and grows, such as a forest,
lake, or stream.
Haze When particles of dust, pollen, or
pollution make the air less clear, and
limit visibility.
Hydroelectric Power Energy that is
generated by dams, which use water to
turn turbines and generate electricity.
Hydrologic Cycle The movement of water
from the atmosphere to the surface of
the land, soil, and plants and back again
to the atmosphere.
Litmus Paper Paper coated with a
chemical coloring obtained from lichens
that turns red in acidic water and blue
in basic water. It is used as an acid-base
indicator.
Meteorological Pertaining to the weather.
Natural Resources All the parts of the
Earth that are not human-made and
which people use, like fish, trees,
minerals, lakes, or rivers.
44
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Neutral A substance that is neither an
acid nor a base and has a pH of 7.
Neutral substances can be created by
combining acids and bases.
Neutralize To combine acids and bases
to make a neutral substance or solution.
For example, acidic water can be
neutralized by adding a base.
Nitric Acid An acid that can be produced
from nitrogen oxide, a pollutant that
results from the burning of fossil fuels.
Nitrogen Oxides (NOX) A family of
gases made up of nitrogen and
oxygen commonly released by
burning fossil fuels.
Nuclear Power Energy that comes from
breaking apart the center (nucleus) of
an atom.
Nutrient Deficiency When a living thing
lacks the vitamins and minerals it needs
to survive.
Ozone A chemical that is made of three
oxygen atoms joined together, and found
in the Earth's atmosphere. There are two
kinds of ozone: good ozone, and bad
ozone. Good ozone is found high in the
Earth's atmosphere, and prevents the
sun's harmful rays from reaching the
Earth. Bad ozone is found low to the
ground, and can be harmful to animals
and humans because it damages our
lungs, sometimes making it difficult to
breathe.
Ozone Layer The layer of ozone that
shields the Earth from the sun's
harmful rays.
Particulate Matter Tiny solid particles or
liquid droplets suspended in the air.
pH Paper Paper that changes color to
show the pH of a substance.
pH Scale The range of units that
indicate whether a substance is acidic,
basic, or neutral. The pH scale ranges
from o to 14.
Photosynthesis The process that plants
use to convert sunlight to energy to live
and grow.
Pollutants Chemicals or other substances
that are harmful to or unwanted in the
environment. Some examples of
pollutants are sulfur dioxide (S02),
nitrogen oxides (NOX), ozone, and
paniculate matter.
Pollution The release of harmful
substances into the environment.
Precipitation Water falling to the Earth.
Mist, sleet, rain, hail, and snow are the
most common kinds of precipitation.
Primary Producers Organisms that use
photosynthesis to produce their own
food. All plants are primary producers.
Primary producers are the base of the
food chain because they feed
everything else.
Reactive Having the tendency to
chemically combine with something
else and change its form. For example,
a strong acid is highly reactive with a
strong base.
K
45
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Respiratory Illness Diseases affecting the
organs we use to breathe. Asthma,
bronchitis, and pneumonia are examples
of respiratory illnesses.
Respiratory System The organs in our
body involved with the process of
breathing.
Runoff Water that flows off land into
lakes and streams.
Scrubber A device that removes air
pollution, mainly sulfur dioxide, from
smokestacks.
Solar Power Electricity that is generated
by harnessing the energy of the sun.
Solar panels are often used to convert
sunlight to energy.
Sulfur Dioxide (S02) A naturally occurring
gas made of sulfur and oxygen that is
also released when fossil fuels are
burned.
Sulfuric Acid An acid that can be
produced in the atmosphere from sulfur
dioxide, a pollutant that results from
burning fossil fuels.
Surface Water Water that is found on the
surface of the Earth in lakes, ponds,
streams, or rivers.
Turbine A motor activated by water,
steam, or air to produce energy.
Wind Power Energy that is generated
when the wind turns the sails of a
windmill, which are attached to turbines
that generate electricity.
46
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&EPA
United States Environmental Protection Agency
Office of Air and Radiation
Office of Atmospheric Programs
Clean Air Markets Division (6204])
1200 Pennsylvania Ave., NW
Washington, D.C. 20460
EPA 430-F-08-002
April 2008
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