Pure and impure

In this topic you will learn about the differences between elements, compounds and mixtures, be able to describe how to make up a solution and describe the different techniques used to separate out the substances in mixtures. 

Task 4b: Make notes that:

• Draw a diagram to show how filtration works.

• Define filtration, filtrate, residue.

• Describe how you would separate sand from a mixture of  sandy water.

Task 5b: Make notes that:

• Draw a diagram to show how evaporation works.

• Define evaporation

Task 6b: Make notes that:

• Draw a diagram to show how distillation works.

• Define distillation.

Copy and complete the following:

Distillation is a way to s_______ a mixture. The mixture is heated until one part of it b____ and turns into a g__. This gas is ________ than the rest of the mixture, so it ______ and moves through a tube into another container. As the gas moves away from the heat, it _____ _____ and changes back into a ______. 

Task 7c: Make notes that:

• Describe the process of chromatography, including why it is useful

• Explain why different dyes travel different distances

Task 7f: Answer the exam questions and self mark

Task 8c: Make notes that:

• Describe what is happening to the particles at each stage of the experiment.

  • What is happening at each step?

• Why do we need to do it?

• What do you have at the start?

• What do you have at the end?

• What is happening to the particles?

• Can you think of any ways you could be wasting salt?