STUDENT SPACE · TOPIC 2
Filtration and crystallisation
Recover both an insoluble solid and a dissolved solid from a mixture.
The essentials
- Filtration separates an insoluble solid from a liquid. The residue stays on the filter paper; the filtrate passes through.
- Dissolved particles pass through filter paper with the solvent.
- To obtain crystals, concentrate a solution by gentle evaporation, allow it to cool, then filter and dry the crystals.
Key vocabulary
| English | Chinese |
|---|---|
| residue | 滤渣 |
| filtrate | 滤液 |
| saturated | 饱和的 |
| crystallisation | 结晶 |
Quick practice
A mixture contains gravel and sugar solution. Which step should come first if you want to collect sugar crystals?
Need a hint?
Remove the insoluble material before concentrating the solution.
Check your reasoning after trying
Filter first to remove the gravel. The sugar remains dissolved in the filtrate and can then be obtained by crystallisation.
Use Lesson 2 in your worksheet for written practice. Your teacher will discuss those answers in class.