Lesson 17: Filtration
What type of mixtures will filtration separate?
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Filtration can remove suspended material from water as long as the pores in the filter paper are smaller than the particles of the suspended substance. Filtration is done by passing a mixture through a filter. The residue is the substance that remains on the filter paper. The filtrate is the substance that flows through the filter paper. Click the red arrow on the animation screen to see each step of the filtration process. Check out these sites to learn more about the various types of filtration! |
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Animation
created
by Joseph
Clark.
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Filtration can remove suspended material from water as long as the pores in the filter paper are smaller than the particles of the suspended substance. Filtration is done by passing a mixture through a filter. The residue is the substance that remains on the filter paper. The filtrate is the substance that flows through the filter paper. Check out these sites to learn more about the various types of filtration!
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Certain mixtures can be separated using filtration. Yet, filtration has no effect on other mixtures.
In this activity, you will make a suspension, a solution, and a colloidal dispersion. Then you will pass each of these mixtures through a filter paper. Through your observations you will learn what type of mixtures filtration will separate.
Part 1: Making mixtures
Make a soil and water suspension, a copper sulfate solution, and a starch dispersion. Use about 100 mL of water and some solute so that your mixture looks similar to the ones shown in the table below. Write a description of each mixture in your data table.
Part 2: Making predictions
Predict whether or not the mixture will be separated by filtration.
Part 3: Do a filtration of each of the mixtures
Pass each mixture through a filter paper using the setup shown in the diagram at the top of this page. Use a fresh filter paper for each. Record your observations about the filtrate and residue.
Part 4: Write a conclusion.
What type(s) of mixtures will filtration separate?
| Mixture |
Soil
and water
suspension
|
Copper
sulfate
and water
solution
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Starch
and water
dispersion
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| Picture |
 |
 |
 |
| Description | |||
| Prediction | |||
| Filtrate | |||
| Residue | |||
| Was the mixture separated? |
Compare your results with the results of your classmates. Look here if you want to see one of my results. Do you all agree on what type(s) of mixture(s) filtration can separate?
The process of filtration is used all around us. Make a large list in table format where you itemize where filtration is used, a description of the mixture undergoing the filtration, a description of the residue, and a description of the filtrate. The first one is done for you as an example.
| Where filtration is used | Original mixture | Residue | Filtrate | |
| 1. | Making coffee | Coffee grinds and water is a heterogeneous brown mixture. The coffee grinds mostly are at the bottom of the brewing basket. | Coffee grinds; homogeneous, solid, dark brown in color | Coffee ready to drink (no grinds); brown liquid and homogeneous |
Feel free to compare your list with one of your classmates.
Hand in your comprehensive list to your teacher for evaluation. Your teacher may also request that you hand in your data table from the activity as well.
Your assignment will be scored out of 10 marks ..... did you find 10 places where filtration is used? Were your descriptions filled in accurately and completely?
If your activity results were to be handed in, this also will be scored out of 10 marks. Your score will be based on the accuracy and completeness of your results. Be sure that you wrote a final conclusion stating what type(s) of mixtures filtration will separate.