pH Activity
Created by Erik Heinemann
Print out or
copy into Word the following information so that you can write or type on it to
answer the questions.
Five of the
top ten most produced chemicals in the
Click on the
link for the following website dealing with pH. When you open the file you will find a pH
scale at the top of the page with a cup of red cabbage water indicator
to the right of the scale and pH paper to the left (a second indicator). Test each of the substances by clicking on
them to fill in the following chart.
|
Substance |
pH |
Color of cabbage water |
Color of pH paper |
|
Lemon juice |
|
|
|
|
Baking soda |
|
|
|
|
Aspirin |
|
|
|
|
Ammonia |
|
|
|
|
Milk of Magnesia |
|
|
|
|
Lava soap |
|
|
|
|
Borax |
|
|
|
|
Lemon soap |
|
|
|
|
Vinegar |
|
|
|
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Tonic water |
|
|
|
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Liquid Plumber |
|
|
|
1) The pH scale shown indicates that the
scale measures from 0 to 14. Where are
acids located on that scale? Where are
bases?
2) Draw a pH scale below placing each of
the substances in the chart above on the scale in appropriate spots.
3) Describe the substances in the pH scale
that are acids. From your experience
with these substances, would you describe their taste as bitter, sweet or
sour? What other properties might these
substances have in common?
4) Describe the substances on the scale that are bases.
From your experience, would you say they have a bitter, sweet or sour
taste? How might you describe the feel
of them?
Click on the
link for the activity labeled Expand from the bottom of the screen. Before
beginning the activity predict which of the following substances would be
work to clean a penny.
|
Substance |
Prediction |
Result |
|
Baking soda |
|
|
|
Vinegar |
|
|
|
Lava soap |
|
|
|
Lemon Juice |
|
|
Click on each
of the substances and record which will be helpful in cleaning pennies in the
table above.
5) Which substances could be used to clean
pennies? Why?
Click on the Explain
icon.
6) What happens when an acid reacts with
water?
7) What happens when a base reacts with
water?
Click on the pH
table highlight on the page and answer the following questions.
8) Consider the safety of direct between
some of the substances on the chart to human skin. What pH range has substances that are safe to
touch?
9) Which pH ranges are unsafe to the human
touch?
10) From the chart, what do you think is the pH
range for foods that we eat? Why?
Conclusion
11) After exploring the concept of pH, write what
have you learned?
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