Acid Showers Sting
May Flowers
Sharing the fun of science and Earth
Day with your kids
Picking up
garbage, recycling or planting trees are all typical Earth Day
activities. Here is a fun and interactive home science
experiment to help your kids understand their community as part
of the global environment.
Maybe your
family is participating in Earth Day by getting muddy while
digging holes and planting trees. After planting the trees you
must have watered them and explained that a good rain would help
them grow up big and strong! But will it?
Forests and
soils are greatly impacted by acid rain. The sulfuric acid in
the rain washes away important soil nutrients necessary for
healthy plant growth and makes plants vulnerable to a variety of
diseases.
With a simple
home science experiment you can test the acidic level of the
rain that falls in your community. You probably have most of the
needed materials in your own home
Begin by talking to your children about what
contributes to acid rain. One of the main causes of acid rain is
sulfur dioxide. Natural sources that emit this gas are volcanoes
and rotting vegetation. However, the burning of fossil fuels,
such as coal and oil, produce approximately half of the
emissions of this gas around the world. Remember to tell your
kids that although these acids are normally too weak to harm
humans, over time these acids can affect plants as well as other
materials.
How do you know
if your rain is acidic? Acidity is measured on a pH scale with a
range of 0 to 14. Substances with a pH of 7 are described as
neutral. A pH lower than 7 means the substance is an acid and
higher than 7 means the substance is a base or alkali. Out of
curiosity, your kids may want to know that pH stands for
potential hydrogen. Acid rain is defined as any rainfall
that has an acidity level or pH value of lower than 5.6. To test
your rain for acidity you will need a pH indicator.
Preparing for
your experiment:
-
Collect
rainwater in a clean container such as a pail or 2-litre
plastic pop bottle with the top cut off.
-
Make your pH
indicator as instructed below.
-
Ensure you
have all the materials listed below.
Materials
-
Sliced
red cabbage
-
1
quart of water
-
1
large pan or microwave casserole dish
-
stove,
microwave or hotplate
-
3
glass cups (preferably clear)
-
white
vinegar
-
ammonia or baking soda
-
1
clean 2-litre pop bottle or clean pail
-
rain
water
-
a pen
and paper
A Natural pH indicator you can use:
Red cabbage juice
contains a chemical that turns from its natural deep purple color
to red in acids and blue in bases. Parents can make it at home
following these instructions carefully:
-
Boil cabbage in a covered pan for 30
minutes or microwave for 10 minutes ensuring that the water
doesn’t boil away. (NOTE: boiling cabbage produces a strong
smell)
-
Let cool before removing the
cabbage.
-
If you are not conducting the
experiment that day, the cabbage juice can be stored in the
fridge for up to a week at which time it should be disposed of.
Experiment
instructions:
-
Pour the cabbage juice into the
three clean glasses until they are about 1/4 full.
-
Add 1/2 teaspoon of vinegar to one
glass and stir with a clean spoon.
-
Add 1/2 teaspoon of ammonia or
baking soda to second cup, stir with a clean spoon.
-
Add about a teaspoon of the
rainwater to third cup, stir with a clean spoon.
-
Observe and record your results
The first cup
should change from deep purple to red, indicating that vinegar is
an acid. The second cup should turn to blue indicating the ammonia
or baking soda is a base. What happened to the third cup? Did it
change red (acid) or blue (base) or stay the same (neutral)? (Your
child may want to test other common household substances such as
clear soda pop or different fruits).
On a different
day, you and your child could take some time to research places
around the world that are dealing with the problems of acid rain.
Encouraging your child’s growth and understanding of science and
the environment makes every day Earth Day.
Mad
Science aims to spark the imagination and curiosity of children by
providing them with fun, entertaining and educational activities
that instill a clear understanding of what science is really about
and how it affects the world around them . For more information
about our Birthday Parties, After-School programs, In-Class
workshops, Pre-school workshops, and Special Events call (727)
895-5595 or (813)655-6643 or visit our website at
www.MadScience.org
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