Name __________________
Foul Water
Introduction:
One of the major challenges in our society is keeping the relatively small amount of fresh
water that we have clean. We use fresh water for a wide variety of activities and many of those
pollute the water. We have developed ways to clean this polluted water. Your challenge is to
purify a sample of “polluted” water to the point where you could use it to wash your hands.
Additional Information:
See page 8 in your text for an example of the data table used to record results and hints
on how to do the lab.
Equipment: Here is a list of possible lab equipment you could use. In your lab book, only
include the ones you actually use in the experiment. Make sure to include the amount of each
that you use.
100 ml of Foul Water, 100 ml graduated cylinder, 150 ml beaker
funnel, ring stand, ring clamp, clay triangle, paper cup, paper clip
filter paper, 125 ml Erlenmeyer flask, 150 g decolorizing charcoal
sand, gravel, rubber hose
Procedure: Use the information on page 8 and 9 in the book as a guide.
1. Develop a data table to record the following observations about your water: color,
clarity, odor, presence of oil, presence of solids, and volume.
2. Record the initial amount of foul water and record observations in the data
table.
3. Use your observations of the foul water to develop 3 tests (experiments) that will
separate the majority of these impurities from the pure water. Remember that your
goal is only to make the water usable for washing, not necessarily for drinking. (Hint:
charcoal is often used to adsorb (attract and hold on its surface) substances that can
give water a bad taste, odor, or cloudy appearance).
4. Write down detailed procedures that you will use to carry out these tests. Make sure
someone that is not in this class could use your procedures to replicate exactly your
experiment.
5. Conduct the experiments. Make sure to clean and put away all materials when done.
Questions:
Answer the following questions in your lab notebook. Make sure to include steps used in
calculations and complete sentences for other questions.
1. What percent of the original foul water sample was recovered as “pure” water?
2. What volume of liquid was lost during purification?
3. What percent of your foul water sample was lost during purification?
4. What does the conductivity test indicate about the purity of water in your “clean”
sample?
Discussion Questions:
5. Why do you think distillation is not used by municipal facilities to purify water?
6. What did each step remove? Explain how you know. Use your observations as
support.
7. Do you think that this purification process is effective? Why or why not? Think
about how much water you recovered, how well the process worked, and long it took, as
well as other characteristics that effected how pure your water was or was not.
8. Research question: What ways is water purified in the “real world”? Do some research
in your book, on-line, or from other sources to see if our process relates to actual
processes or not. Relate the real world to the lab. Look in your textbook, or on the
internet (use a search engine and type in “water treatment.”) Try
http://ga.water.usgs.gov/edu/wwvisit.html if you get stuck.
Rubric for Grading: Point values for each section are listed.
Date and
Title
Hypothesis
Materials
(10 points)
Procedure
(15 points)
Data Table
(10 points)
Answers to
Questions
(25 points)
GUM
(10 points)
Date and Title is missing?
Date or Title missing?
Date and Title complete
No Hypothesis?
Hypothesis is there, but
needs more thought and
detail
Hypothesis demonstrates that you
put some thought into or did some
research before making hypothesis.
No Materials?
Materials list incomplete
Materials list complete
Your procedure needs
work. It is missing major
steps needed for others to
repeat the experiment o is
very hard to follow.
Your procedure is mostly
okay. You are probably
missing some minor steps
needed for others to repeat
the experiment.
Your procedure is excellent — wellwritten, complete, and easy for
anyone else to repeat the experiment.
Data table is less than half
complete or inaccurate.
Your data table is mostly
complete and accurate.
Your data table is complete and
accurate.
Answers to conclusion
questions are missing or
inaccurate.
Answers to conclusion
questions are mostly
complete and accurate and
in complete sentences.
Answers to conclusion questions are
complete and accurate and in
complete sentences.
May be badly organized,
messy, or have many
examples of poor
grammar, or may have
been turned in late.
Some disorganization, a bit
messy, or a few
grammatical errors.
Mostly good to excellent in terms of
organization, neatness, and GUM.