New
New
Year 7

Simple distillation

I can describe how distillation is used to separate and recover a liquid from a solution.

New
New
Year 7

Simple distillation

I can describe how distillation is used to separate and recover a liquid from a solution.

Lesson details

Key learning points

  1. A liquid can be separated from a solution by vaporising it and then quickly condensing it.
  2. Distillation works due to one part of a solution having a different boiling point than the other part.
  3. A condenser should be kept cold to speed up condensation.
  4. The liquid collected (distillate) is pure.

Common misconception

Students struggle to understand gas state; thinking solids, liquids and gases as 'types' of matter.

Refer to/use particle models to help clarify different states of matter and use these to describe why separation techniques work.

Keywords

  • Distillation - Distillation is a separation technique that uses boiling and condensation to remove and isolate a liquid part of a mixture.

  • Condensation - Condensation is the process by which a substance in the gas state is cooled and changes to a liquid state.

  • Delivery tube - A delivery tube is a thin tube used to transfer (i.e. "deliver") a substance (usually in the gas state) from one container to another.

  • Condenser - A condenser is a piece of apparatus composed of a tube surrounded by a cold layer, usually cold water.

  • Distillate - The liquid that is condensed from the gas state during distillation is called the distillate.

Try demonstrating the distillation of cherry cola as an alternative to the classic copper sulphate or ink and water. The oil should distil before the water.
Teacher tip

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which of the following processes describe when a substance in the liquid state turns into the gas state?
melting
Correct answer: boiling
condensing
Correct answer: evaporating
freezing
Q2.
Which property of matter does not change when a substance changes state?
shape
volume
Correct answer: mass
state
Q3.
What laboratory equipment is used to measure the volume of liquids accurately?
Bunsen burner
Beaker
Correct answer: Measuring cylinder
Balance
Conical flask
Q4.
True or false? The boiling point of a liquid is the temperature at which it becomes a gas.
Correct answer: True
False
Q5.
Sort the following substances from the one which will boil first to the substance which will boil last when heated.
1 - ethanol boils at 78℃
2 - water boils at 100℃
3 - sodium chloride boils at 1465℃
4 - aluminium boils at 2519℃
Q6.
Match up the processes below to their descriptions
Correct Answer:Evaporation,Where a liquid turns into a gas at the substance's surface.

Where a liquid turns into a gas at the substance's surface.

Correct Answer:Boiling,Where a liquid turns into a gas at a specific temperature.

Where a liquid turns into a gas at a specific temperature.

Correct Answer:Condensation,Where a gas is changed into a liquid.

Where a gas is changed into a liquid.

6 Questions

Q1.
What is the main purpose of distillation?
To mix two substances.
Correct answer: To isolate the liquid part of a mixture.
To change a liquid's colour.
To decrease the boiling point of a liquid.
Q2.
True or false? The distillate collected after distillation is typically an impure substance.
True
Correct answer: False
Q3.
What does it mean if a substance has a high boiling point?
It changes into a vapour at a lower temperature.
It is less dense than water.
Correct answer: It requires more heat to convert into a vapour.
It is not suitable for distillation.
Q4.
Which piece of a distillation apparatus is cooled to condense the vapour back into a liquid?
Correct Answer: condenser, liebig condenser
Q5.
During distillation a liquid is turned into a vapour and then cooled back into a liquid, the liquid produced is called the ...
Correct Answer: distillate
Q6.
A mixture contains ethanol and water, which separation technique can be used to separate these liquids?
Correct Answer: distillation