Seperating Mixtures

Question 0

What are the six methods of separation?

Answer 0

Sieving, decanting, magnetic separation, gravity separation, evaporation and filtration.

Question 1

Why do we need to be able to separate mixtures?

Answer 1

Because it has many uses in a number of industries.

Question 2

What is sieving?

Answer 2

When two solids are mixed together and the solid particles are of different sizes. (One is larger than the other)

OR

For a solid and a liquid mixture where the particles of the solid are quite large.

Question 3

What are some examples of sieving?

Answer 3

• refining metals from their ores

Larger screening sieves are used to separate small chunks of ore from large ones, which require further crushing

Question 4

What is decanting?

Answer 4

It is used to separate suspensions. Allow the sediment to settle at the bottom of the container then carefully pour the liquid off the top. Some examples are: sand and water, oil red wine sometimes forms a sediment and can be decanted.

Question 5

What is magnetic separation?

Answer 5

A magnet is used to separate nails (iron) and toothpicks. It is used in the mining industry.

Question 6

What is gravity separation ?

Answer 6

When you use gravity to separate a mixture. If a mixture containing water and particles of different weights is stirred or shaken, the heavier particles will tend to migrate towards the bottom of the container. Some examples are gold panning.

Question 7

What is evaporation? (Separation)

Answer 7

Used to separate a solid from a liquid or a solid from a solution. You heat the solution which causes the water to evaporate. Some examples are: salt and water from sea water, the food industry - to produce dried fruit or evaporated milk.

Question 8

What is filtration ?

Answer 8

It is used to separate solids form liquids. Filter paper is used to to allow the liquid to pass through the, but to stop larger solid particles from passing through. Some examples are: filtered coffee, tea bags,