Testing pH
This is the title part 
Introduction
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Background:
Universal indicator paper changes color
depending on the pH of the solution.
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Acidic things have a low pH and lots of
Hydrogen. (0-6)
Basic things have a high pH and a low
amount of Hydrogen. (8-14)
Things that are neutral are at 7
pH is a scale of 0-14
pH scale
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LOTS OF
HYDROGEN
IONS
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FEWER
HYDROGEN
IONS
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The pH scale
measures how acidic
or basic a substance
is.
The pH scale ranges
from 0 to 14.
A pH of 7 is neutral.
A pH less than 7 is
acidic.
A pH greater than 7
is basic.
http://www.youtube.com/wa
tch?v=M8tTELZD5Ek
Purpose:
 Which
substances
that you
have do you
think will be
basic,
neutral, and
acidic?
Hypothesis:
I think the:
 Lemon juice is…because…
 Milk… is…because…
 Windex…
 Ammonia...
 Water…
 Vinegar…
Materials and Equipment
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Beakers
pH indicator paper
See hypothesis for substances
Procedure
 Test
each solution with a new pH
paper indicator strip.
 Write down the results for each
test.
DATA
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Construct a pH scale ranging from 0-14
Place the solutions on this scale.
DATA
Solution
Water
Milk
Ammonia
Lemon Juice
Windex
Vinegar
pH #
Data Analysis
1.
2.
3.
What does your data
represent (what is the
dependent variable
What do the high numbers
and low numbers represent?
What was the independent
variable?
Error Analysis
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1. What was the control?
2. What things did you hold constant
3. Could you have done anything better or
did you make any mistakes?
4. What would you do differently next
time?
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Could you try to make anything more
constant to be fair?
What other factor would you want to test
Make a new hypothesis or what do you want
to test for next time?
Conclusions
1. Were your hypotheses correct?
2. Did any of these substances surprise you?
(which ones did you guess wrong on?)
3. What did you find out about cleaning
agents?
4. What did you find out about water?
5. What does changing the pH do to
enzymes?
References

Biology textbook:
 Nowicki,
Stephen, Ph.D.
Biology. McDougal Little, 2008
(p. 43).
PH SCALE ON YOUTUBE