Explain how distillation recovers a solvent or separates a mixture of liquids.
| English | Chinese |
|---|---|
| distillation | 蒸馏 |
| condenser | 冷凝器 |
| distillate | 馏出液 |
| fractionating column | 分馏柱 |
Try each question before opening its hint or answer. Use paper for calculations and diagrams.
You need the liquid solvent from a solution. Why is evaporation alone unsuitable?
What happens to the vapour if there is no condenser?
Evaporation lets the solvent escape as vapour. Distillation condenses that vapour so the solvent can be collected.
Describe how to obtain water from salt solution. Include the changes of state and the purpose of the condenser.
Follow water through evaporation and condensation.
Use simple distillation. Water vaporises in the heated flask and condenses in the cooled condenser. Collect the liquid water. Salt remains in the flask.
Why is a fractionating column useful for separating two miscible liquids with similar boiling points? Which component is enriched in the first fraction?
Think about repeated changes of state in the column.
Repeated vaporisation and condensation improve separation. The first fraction is enriched in the component with the lower boiling point.
Use Lesson 3 in your worksheet for written practice. Your teacher will discuss those answers in class.
Choose a method before revealing the outcome. Explain which physical property makes it work.
Your task: collect dry sand.
Explain: does your method depend on solubility, volatility or different boiling points? Schematic decision model; no real apparatus is operated.