Separation Techniques

About this practical...

As well as describing these processes in theory, try your skill at separating a selection of substances through the methods that you have learned.


1. Pass your mixture through the course sieve. This should remove all of the dried peas

2. Cover a magnet in cling film to protect it. Not move it through the dried mixture and it should remove all of the iron

3. Add hot water to the remaining mixture and stir, this should move all of the salt into solution

4. Pass the remainder through a filter paper, the solid sand should now have been separated from the salt solution

5. Place the salt solution into an evaporation dish and heat with a Bunsen on a blue flame. (Do Not heat until dry, it is essential that you leave some water left behind)

6. Leave the remainder of the salt solution to cool and crystalise

Safety & Managing Risks

Usual lab rules must be followed: loose hair tied back, goggles worn throughout the lesson, bags and stools tucked away and notify the teacher of any spills or breakages immediately. Take care when using the Bunsen. It is crucial that you do not boil the solution dry in the evaporation dish as it will spit and hot crystals will potentially land on people. For more detailed information, please consult CLEAPSS.

Technician notes:

Sample pots mixed containing dried peas, salt, iron filings and sand

Filter papers

Filter funnels

Conical flasks

Magnets & clingfilm

Sieves and tweezers

Evaporating basins

This page was updated on: 8th January 2022