New
New
Year 10
Edexcel
Higher

Distillation: fractional distillation

I can explain how fractional distillation works and how it differs from simple distillation in separating mixtures of fluids.

New
New
Year 10
Edexcel
Higher

Distillation: fractional distillation

I can explain how fractional distillation works and how it differs from simple distillation in separating mixtures of fluids.

Share activities with pupils
Share function coming soon...

Lesson details

Key learning points

  1. Fractional distillation is an extension of simple distillation, and is mostly used to separate mixtures of liquids.
  2. A main distinction between fractional and simple distillation is that the former uses a fractionating column.
  3. Fractional distillation has multiple real-world examples, including the fractional distillation of air.
  4. Fractional distillation produces fractions; these can be pure or mixtures of chemicals with very similar boiling points.

Common misconception

Students sometimes think that heating a substance strongly and for extended periods will improve the quality of separation via distillation.

Stress that distillation is a skill which requires careful control of heating so only one substance is in the condenser at a time. Understanding the link between application of heat to the mixture, boiling point and reading a thermometer is essential

Keywords

  • Fraction - A fraction is a component of a mixture that has been separated by fractional distillation.

  • Fractional distillation - Fractional distillation is a method used to separate miscible fluids (liquids or gases) with different boiling points into individual components (fractions).

  • Miscible - Fluids that dissolve in another fluid are described as miscible in that fluid.

  • Boiling point - The temperature at which a substance changes between a liquid state and a gas state is known as its boiling point.

  • Fractionating column - A fractionating column is a piece of apparatus within which a temperature gradient develops. It is used during fractional distillation.

Have 'simple' and fractional distillation set ups and compare / contrast them. Use fractional distillation to separate ethanol from water then compare the flammability of the distillate and the starting mixture.
Teacher tip

Content guidance

  • Contains subject matter which individuals may find upsetting.
  • Equipment requiring safe usage.

Supervision

Adult supervision recommended.

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).

Video

Loading...

6 Questions

Q1.
A mixture is a substance which is made up from more than one element and/or compound which are ...
chemically bonded together.
Correct answer: not chemically bonded together.
always have the same boiling point.
always in the same state.
Q2.
is the process by which a gas is cooled into a liquid.
Correct Answer: condensation
Q3.
Air is an example of ...
an element.
a compound.
Correct answer: a mixture.
Q4.
Match the following statements to make complete sentences about pure substances and mixtures.
Correct Answer:A pure substance boils ...,at a fixed temperature.

at a fixed temperature.

Correct Answer:A mixture boils ...,over a range of temperatures.

over a range of temperatures.

Correct Answer:A pure substance consists ...,of one element or compound only.

of one element or compound only.

Correct Answer:A mixture consists ...,of more than one element and/or compound.

of more than one element and/or compound.

Correct Answer:A pure substance can ...,not be separated.

not be separated.

Correct Answer:A mixture can ...,be separated.

be separated.

Q5.
Simple distillation can be used to separate solutions. Order the following processes that occur during simple distillation.
1 - Heat the mixture.
2 - The component with lowest boiling point boils.
3 - Vapour is cooled.
4 - Vapour condenses.
5 - Distillate is collected.
Q6.
In the diagram below, give the letters in order for where forces between the particles are overcome or where they are being reformed.
An image in a quiz
c and b
b and c
Correct answer: a and b
c and a
b and a

6 Questions

Q1.
What are miscible fluids?
liquid and solid substances that can mix
Correct answer: liquids and/or gases which can dissolve in each other
any liquids that are mixed together
Q2.
are produced by fractional distillation. They may be pure, i.e. contain one component, or a mixture containing multiple components with similar boiling points.
Correct Answer: fractions
Q3.
What is the purpose of fractional distillation?
to mix multiple fluids together with different boiling points
Correct answer: to separate multiple fluids with different boiling points
to produce a single fraction
to produce a single pure fluid
Q4.
Match the following statements to make complete sentences related to distillation:
Correct Answer:Simple distillation can be used to ... ,separate two miscible liquids with very different boiling points.

separate two miscible liquids with very different boiling points.

Correct Answer:Fractional distillation can be used ...,to separate multiple miscible fluids with a range of boiling points.

to separate multiple miscible fluids with a range of boiling points.

Correct Answer:A fractionating column can be used ...,to create a temperature gradient to separate fluids into fractions.

to create a temperature gradient to separate fluids into fractions.

Correct Answer:Fractions are ...,pure substances, or mixtures with similar boiling points.

pure substances, or mixtures with similar boiling points.

Q5.
A mixture of liquid fractions; X (b.p. 40 - 100°C), Y (b.p. 120 - 160°C) and Z (b.p. 180 - 200°C) was heated quickly to 150°C. What would be found in the distillate?
X, Y and Z
X only
Correct answer: X and Y
Y
Q6.
Match the letter with the correct statement concerning the steps occurring during fractional distillation.
An image in a quiz
Correct Answer:a,miscible fluid mixture is heated and starts to boil forming a vapour

miscible fluid mixture is heated and starts to boil forming a vapour

Correct Answer:b,the vapour passes up the fractionating column, heating the bottom

the vapour passes up the fractionating column, heating the bottom

Correct Answer:c,most substances cool as they rise up the column and drip back down

most substances cool as they rise up the column and drip back down

Correct Answer:d,lower boiling point substances pass as gases into the condenser

lower boiling point substances pass as gases into the condenser

Correct Answer:e,these gases are cooled in the condenser back into the liquid state

these gases are cooled in the condenser back into the liquid state

Correct Answer:f,the condensed liquid is collected as the distillate fraction

the condensed liquid is collected as the distillate fraction