Separating Mixtures
≈ 25 minBecause the parts of a mixture keep their own properties, we can separate them using physical methods — no new substances are made. The method you choose depends on a property that differs between the parts:
| Method | Uses the difference in… | Everyday example |
|---|---|---|
| Filtration | particle size (solid vs liquid) | straining tea leaves |
| Evaporation | boiling point (dissolved solid stays) | getting salt from sea water |
| Distillation | boiling point (collect the vapour) | purifying water |
| Magnetism | magnetic vs non-magnetic | pulling iron filings from sand |
| Hand sorting / sieving | size or appearance | sorting maize from stones |
Filtration traps an undissolved solid on filter paper while the liquid (the filtrate) passes through. Evaporation boils the liquid away and leaves a dissolved solid behind.
You want to recover dissolved salt from salt water. The best method is…
Which method would best separate iron filings from a pile of sand?
What single word names the clear liquid that passes through the filter paper during filtration?