Filtration And Crystalisation

Question 1

How are mixtures separated by filtration?

Answer 1

Weigh out 3g rock salt
Use pestle and mortar to crush the salt into powder
Add 20ml distilled water to the rock salt, use glass rod to mix it
Fold filter paper into a funnel, put it onto the conical flask
Pour the mixture slowly down the filter paper conical flask
When it’s been filtered put the filter paper (with the sand) in the bin and pour the filtrate into the evaporating basin
Fill the 250ml beaker up with 150ml of tap water
Then put it onto the tripod and gauze mat over a Bunsen burner
Put the evaporating basin on top of the beaker
The light the Bunsen burner, put it onto a roaring flame
At the end all of the distilled water will have evaporated, the salt will be round the side

Question 2

Why does the temperature not change as a pure substance melts?

Answer 2

Because a pure substance has the same composition throughout it so all of the substance will melt at the same temperature

Question 3

What equipment we use for filtration and crystallisation?

Answer 3

3g rock salt, 150 ml water, 20ml distilled water, Bunsen burner, tripod, heat proof mat, weighing boat, pestle and mortar, conical flask, beaker, glass rod, gauze mat, filter paper, evaporating basin, balance, measuring cylinder

Question 4

State 3 ways that you can reduce risk when doing filtration and crystalisation

Answer 4

The Bunsen burner can burn you - try and keep it as far away as possible
Glass can smash - handle with care
The beaker can be hot - be careful with it

Question 5

What is the formation of crystals during crystallisation?

Answer 5

When the solution evaporates it leaves the salt crystals around the ride of the evaporation basin

Question 6

State some mixtures that can be separated by filtration

Answer 6

Sand and water

Sand and pebbles

Question 7

What are the steps of crystallisation?

Answer 7

Heat
Bubble
Leave to evaporate
Rinse in distilled water

Question 8

What are filters used for?

Answer 8

Filters can be used to separate some mixtures,not hey let smaller pieces or liquids through but trap bigger pieces or insoluble substances

Question 9

What is crystallisation?

Answer 9

It’s the process that forms solid crystals of various sizes by evaporating the solvent to leave the solutes behind

Question 10

What is a saturated solution?

Answer 10

It means it contains the maximum amount of solute that can dissolve in that amount of solvent at that temperature