C1 Seperation Techniques

Question 1

What is different between a compound and a mixture?

Answer 1

There are no chemcial bonds in a mixture therefore they are easily seperated usong phycical methods.

The chemical properties of a subastance arn’t effected by them being a mixture.

Question 2

What are the methods of seperation of mixtures?

Answer 2

Filtracion
Crystallisation
Simple distillation 
Fractional distillation
Chromotography

Question 3

What does filtration seperate?

Answer 3

Insoluable solids from a liquid

Question 4

How do you do filtration?

Answer 4

You need some filter papper (with small holes in it) you but it in a cone shape and put it on top of a beaker. You then pore the solution into the filter paper and you will be left with a beaker of liquid (because the liquid molecules can fit through the filtration paper and in the filter paper you will have a solid becasue it can’t fit though the holes.

Question 5

How can you seperate soluable solids from a liquid?

Answer 5

Evaporation

Crystallisation

Question 6

What is Crystallisation?

Answer 6

1) You pore some water into an evaporation dish and gently heat the solution
2) once some of the solvent has evaporated (meaning that one of the solitions is highly concentrated) or crystalls have start to form (the point of crystallisation) you remove the dish from the heat and let it cool
3) if you have don’t this with salt water the salt would have formed crystalls because it becomes insoluable in the cold and highly concentrated solution
4) you then need to filter the crystals out of the solution using another method eg filtration

Question 7

What is rock salt?

Answer 7

A mixture of salt and sand.

Question 8

How do you sepearate rock salt?

Answer 8

Salt disolves in eater whilst sand won’t

If you disolve the rock salt into water (by stiring) you can use filtration to seperate the solution from the sand

You can then use evaporation to seperate the water and salt

This leaves you with water, salt and sand

Question 9

What is evaporation?

Answer 9

1) Pore the solution into an evaporating dish
2) Slowly heat the solition. Eventually one solition will evaporate and the solid will form crystals as it is insoluable in concentrated solution.
3) continue heating untill there is no solution left.

This is a quick way to seperate things but you can only use it if the liquid will evaporate before the salt will