Experiment | Filtering a Suspension

Approximate time to complete: 15-25 minutes + waiting time + questions and journal time

Experiment Card

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Filtering a Suspension Download

Purpose

There are many different ways to separate a mixture. One of those ways is through a filter. I wonder what kinds of mixtures can be separated by a filter.

Materials

3 Beakers
3 Test Tubes with Caps
Test Tube Holder
Funnel
Sand
NaCl (salt)
CaCO3 (Chalk Powder)
Water
3 Pieces Filter Paper

Procedure

Using your funnel, fill ¼ of the first test tube with sand, ¼ of the second test tube with chalk powder, and ¼ of the third test tube with salt.
Using your pipette, fill each test tube with water until it is ¾ full. Put a cap on each test tube.
Fold each piece of filter paper into a cone shape, and place it into a beaker.
- Directions for folding your filter paper are at the bottom of this page.
Place your thumb over the cap, and vigorously shake each test tube. Observe what happens to the particles inside.
- Make sure that all of the salt dissolves into the water. If it will not all dissolve, you can pour part of the solution out of the test tube, and add more water until the salt dissolves.
Remove the cap from each test tube, and pour the contents into your three filtration devices. (Sand mixture into the first beaker, chalk powder mixture into the second beaker, and salt mixture into the third beaker). Observe what happens.
Leave your set up for 10-20 minutes, and check on it again.

Questions & Further Research

What is a suspension? What is a solution?
Are the following mixtures SOLUTIONS or SUSPENSIONS?
- Sand and Water
- Chalk powder and water
- Salt and Water
How do filters work?
What are some examples of filters outside of the science lab? Think about your everyday life, and about big factories or machines.

Combining and Separating

Prep