Help Mrs Johal to clean up after her messy class by separating sand, sawdust and salt
This session should take 60 minutes.
- Filter funnels
- Filter papers
- Hand lens
- Mixture of sand/salt/sawdust
Health, safety and technical notes
- Read our standard health and safety guidance here.
- Wear eye or clothing protection if desired.
- This is an open-ended problem-solving activity, so the guidance given here is necessarily incomplete.
- There are no significant hazards associated with this experiment.
Questions to ask students who need help are:
- Do you think magnets should work?
- What about a sieve?
- A home-made sieve?
- Could you use tweezers and a hand lens to pick out the pieces?
- What about using water? – Floaters/sinkers, dissolving.
Few students realise that only a small amount of water is needed to dissolve the salt. If a large amount of water is used, it can take a long time to evaporate.
The final drying of the salt and the sand can be done in an oven.
Students could design a large scale separation plant that works continuously. Separate chocolate bits from chocolate chip cookies.
- Experiment | PDF, Size 14.07 kb
The resources were originally published in the book In Search of Solution P. Borrows, K. Davies and R. Lewin, Royal Society of Chemistry, 1990.
This experiment was based on an idea contributed by P. Borrows.