Separation Techniques

Question 1

Give two methods of separating mixtures

Answer 1

Crystallisation and filtration

Question 2

What does filtration separate?

Answer 2

Insoluble solids from liquids

Question 3

What two methods can be used to separate a soluble salt from a solution?

Answer 3

Evaporation and crystallisation

Question 4

What is the experiment for evaporation?

Answer 4

1) pour the solution into an evaporating dish
2) slowly heat the solution. The solvent will evaporate and the solution will get more concentrated. Eventually crystals will start to form.
3) keep heating the evaporating dish until all you have left are dry crystals

Question 5

In what case can you NOT use evaporation as a way of separating a soluble salt from a solution?

Answer 5

If the salt decomposes (breaks down) when its heated.

Question 6

What method do you use to separate a soluble salt from a solution if the salt does decompose ?

Answer 6

Crystallisation

Question 7

Explain the steps of the crystallisation experiment

Answer 7

1) pour the solution into an evaporating dish and gently heat the solution
2) once some of the solvent has evaporated or when you see crystals starting to form, remove the dish from the heat and leave the solution to cool
3) the salt should start to from crystals
4) filter the crystals out of the solution and leave them in a warm place to dry.

Question 8

True or false?
Filtration and crystallisation can be used to separate rock salt

Answer 8

True

Question 9

What is rock salt?

Answer 9

A mixture of salt and sand