Filtration can be a simple technique used to separate insoluble solids from a mixture or suspension. It has a lot of everyday applications.
Filter first
Filtration is any of various mechanical, physical or biological operations that separates solids from fluids by adding a medium through which only the fluid can pass.
The fluid that passes through is called the filtrate.
A fluid is a liquid or gas
Here we will consider filtration as a simple technique used to separate insoluble solids from a mixture with or suspension in a liquid.
Sometimes it is the filtrate that we want to isolate ( as in the making of a cup of coffee), on other occasions it is the residue that is left behind in the filter that is of value to us.
Activity 1. Faster filtration
In the laboratory suction filtration can speed up the process and help to dry the insoluble residue on the filter paper.
Task 1
Make a copy of the suction filtration diagram. Add labels to the diagram to help explain why a vacuum pump is used.
What's the connection?
Odd one out?
Compare the four images shown here.
All four images represent a type of filtration.
Copy and complete the table below:
| | Filtrate | Residue ("filtride") |
| Figure 1 | | |
| Figure 2 | | |
| Figure 3 | | |
| Figure 4 | | |
Which image is the odd one out and why ? ( there is more than one acceptable answer - so long as you justify it)