Separation of Solutions and Mixtures
Introduced| English | Meaning |
|---|---|
| filtration/fɪlˈtreɪʃn/ | Separating insoluble particles from a fluid by passing the mixture through a porous barrier. |
| evaporation/ɪˌvæpəˈreɪʃn/ | The escape of particles from the surface of a liquid into its vapour without the whole liquid boiling. |
| chromatography/krəʊməˈtɒɡrəfi/ | A separation technique based on different affinities of substances for a stationary phase and a mobile phase. |
| distillation/dɪstɪˈleɪʃn/ | Separating substances by vaporising and condensing them, using differences in volatility or boiling point. |
Pulling a blend apart
- A muddy river can be made clear again.
- Salt can be recovered from the sea by the sun.
- Ink can be split into its hidden colours.
- Each trick exploits one way the parts differ.
Filtration and evaporation
- Filtration 过滤 separates by particle size: solids are caught, liquid passes.
- Evaporation 蒸发 leaves a dissolved solid behind as the solvent boils off.
- Use filtration for undissolved solids, evaporation for dissolved ones.
Paper chromatography 色谱法 separates a mixture as the solvent rises up the paper
Filtration separates a mixture based on differences in...
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Large solids are trapped while liquid passes through the filter.
To recover dissolved salt from salt water while discarding the water, use...
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Boiling off the water leaves the solid salt behind.
Distillation
- Distillation 蒸馏 separates liquids by their boiling points.
- The lower-boiling liquid vaporizes first, then re-condenses cleanly.
- It is how alcohol is separated from water.
To separate pure water from salt water, you would use...
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Distillation boils off the water and re-condenses it, leaving salt behind.
Chromatography
- Chromatography separates by how strongly each part clings to a surface.
- The components travel at different speeds and spread out.
- Ink's dyes separate into a rainbow of bands.
Pick the separation method
Match each mixture to the technique that separates it, and the property it exploits.
Match each method to the property it uses.
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Distillation = boiling point, filtration = size, chromatography = affinity.
Chromatography separates ink dyes because each travels at a different ____.
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Dyes that cling more strongly move more slowly, so they spread apart.
How would you get pure water from salt water?
- Distil it: boil the water off and re-condense the vapour.
- The salt stays behind, and the collected liquid is pure water.
Filtration can separate a dissolved solute from its solvent.
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Dissolved particles pass through the filter; use evaporation or distillation.
Each method exploits one specific difference — size for filtration, boiling point for distillation, surface affinity for chromatography. Filtration cannot separate a dissolved solute (it passes through the filter); use evaporation or distillation for that. Match the method to the property that differs.
Separation methods each exploit a property difference: filtration by particle size, evaporation to recover a dissolved solid, distillation by boiling point, and chromatography by surface affinity. A dissolved solute passes through a filter, so recover it by evaporation or distillation instead.