Lesson 4: Separation by distillation Flashcards
What is simple distillation?
- Separation technique used to separate a soluble solid from a liquid, when you want to keep the liquid.
What is the process of solid–> liquid known as?
- Melting
What is the process of liquid –> gas known as?
- Boiling
What is the process of gas —> liquid known as?
- Condensation
What is the process of liquid —> solid known as?
- Freezing
What is the name of the liquid that is collected at the end of distillation?
The liquid collected at the end of distillation is the “distillate.”
Name the apparatus in which a gas turns into a liquid during distillation.
The apparatus where a gas —> liquid is known as a “condenser.”
What is the boiling point of water?
100 °C
In order for a mixture of two liquids to be separated, what must be different?
- Their boiling points must be different for them to separate.
What are the 3 main steps of distillation?
1.) Heat and vaporise
2.) Cool and condense
3.) Collect distillate
What substance evaporates first?
The substance with the lowest boiling point will evaporate first.
What type of changes are melting, evaporated, condensing and freezing known as?
- Physical changes.
- Do not involve chemical reactions.
- No new substances are made.
Where is the mixture heated in distillation?
- Mixture is heated in round- bottomed flask.
What is fractional distillation?
- A separation technique that separates a mixture of liquids.
Give 2 examples of fractional distillation.
- Separating water and ethanol
- Crude oil separation
What is the boiling point of ethanol?
78⁰C
Why is the top of a distilation column always colder than the bottom?
- This is because the vapour is further away from the heat source.
- It starts to condense*
What is the name of the powder used that stops vigorous heating?
- Antibumping powder will stop vigorous heating.
What is a better way to heat rather than using a bunsen burner?
- Use an electric heater to control the temperature.
How could the water be tested to show it is pure?
Give the expected result of the test for pure water
- Determine boiling point
- Should be 100°C
