foul water lab - sciencewithwatson

Chemistry in the Community
Foul Water Lab
Name: ________________________
Date: _________________________
Lab Partners: ___________________
Purpose: The goal of this lab activity is to think about whether a particular sample of water is clean
enough for using and to learn about some methods for cleaning water.
Before You Begin:
Look at the three samples of water in the front of the room. Just by looking at them, answer the
following questions.
1. Do you think any of the samples are clean enough to drink? How could you tell?
2. Do you think any of the samples are clean enough to swim in? How could you tell?
3. Find out the identity of the water sources. Does knowing where they are from change any of
your answers to questions 1 and 2? EXPLAIN
Procedure: Obtain a copy of the procedure. You will only be completing this procedure for the “foul
water” sample. Since you are following the directions from a book, you do not need to write the
procedures out in detail. Before you begin, answer the following questions about the procedure:
List the three steps below that you will complete to purify the water. State the purpose of each step.
1. Step:
2. Step:
3. Step
1. Record your data and observations in the chart below.
Presence of
Presence of
Volume, ml
After Step 1
After Step 2
After Step 3
Based on the water uses that we listed in class, decide which uses are appropriate for the water after each step.
2. Describe your final purified water sample:
Other details:
3. What was the volume of purified water recovered? ____________________
What total volume of foul water did you start with? ____________________
4. Describe the results of the conductivity test. (What substances were tested and what did you
Questions and Conclusions
1. Why did the method that you used to separate the oil and water work? Could you separate any two
liquids using this method?
2. What did the conductivity test reveal about the water sample before and after the distillation
procedure? Explain your answer clearly.
3. What was the purpose of the distillation procedure?
4. What percent of the original foul-water sample did you recover as purified water? Show your work.
5. Based on this lab, explain whether you think you were successful in purifying the water sample.
6. Look back at the original three samples of water. Do you think that the process that you did in this
lab would be effective for purifying all of the samples? Is this process necessary? Does what you are
using the water for change your answer? EXPLAIN.
7. Why is distillation NOT used to purify water in municipal water treatment plants?
8. Your job is to design a water treatment process to provide water for a town. Based on this lab, what
do you think are the three MOST IMPORTANT things to consider in developing your process?