Foul Water Lab Pgs. 8-10 in Chem Com text
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Problem or Question:
Hypothesis:
Four Steps of Water Treatment (Write a brief summary of steps in text with a definition of each
underlined term)
1.
2.
3.
4.
Physical Separation
Sand and pebble Filtration
Charcoal Adsorption
Distillation (as a demonstration)
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Post lab activities p. 10.
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Electrical Conductivity test
1a.
1b.
1c.
Questions/Conclusions/Discussion
1. Why is the distillation process not used in water treatment plants?
2. On a scale of 1-5 with 5 being very pure, rate the quality of your filtered water sample and
explain.
3. Would repeating any of the tests help the purity of your sample? If so, which one(s)?
4. What was the final volume of water, in mL, when treatment was complete?
5. What is the volume of water in cm3?
6. What do the results of electrical conductivity test reveal about the water sample? Positive
results means there are dissolved ions in the water. Describe an ion.
7. Dissolved solids may be removed by distillation. Distillation is based on the physical property of?
8. How does the clarity of your sample compare to the other samples in the class?
9. Before distillation, electrical conductivity showed a _____result. This is because (explain)
10. After distillation, electrical conductivity showed________(explain)
11. The physical separation of materials from the water molecules occurred in the process of ___
12. Calculate the percentage of the original sample recovered as pure water. Show formula, plug in
numbers and answer below.
To help you solve problem in #12 answer the following:
What volume of water did you start with? What volume of water did you end up with? What is
the difference between the volumes of foul and pure water?
Foul water – pure water = 100 mL -? mL= %
13.
14.
15.
16.
17.
What % of the original sample of foul water was lost during purification?
Why is it important to know how much water is lost during purification?
The purpose of the sand –gravel purification step was to remove?
The purpose of the charcoal adsorption was to remove?
The reason you could skim the oil off the top of the water was because oil is
_______than________. The density of water is__________ and the density of oil must therefore
be ______________.