More separation techniques

Question 1

Filtration

Answer 1

separates insoluble salts from liquid - often used in purification

filter paper folded into cone shape, solid is left in the filter paper

Question 2

What are the two methods used to separate soluble salt from solution

Answer 2

evaporation and crystallisation

Question 3

Evaporation - quick and use it for salts that don’t decompose

Answer 3

1) Pour solution into evaporation dish and slowly heat the solution
2) The solvent will evaporate and the solution will start to get more concentrated .
3) eventually crystals form. Keep heating the evaporating dish until all you have left is dry crystals

Question 4

Crystallisation

Answer 4

1) Pour solution into evaporation dish and slowly heat the solution - some solvent will evaporate and the solution will get more concentrated .
2)once some of the solvent has evaporated or when you see crystals start to form , remove dish from heat and leave the solution to cool

3) salt will become crystals as its insoluble in cold, highly concentrated solution
4) filter the crystals out the solution and leave them in warm place to dry . You could use drying oven or desiccator

Question 5

What is rock salt ?

Answer 5

mixture of salt and sand which are both compounds but salt dissolves in water and sand doesn’t. This difference in property allows them to be separated

Question 6

Way to separate rock salt

Answer 6

1) Grind mixture to make sure salt crystals are small and will dissolve easily
2) Put mixture in water and stir. The salt will dissolve, sand won’t

3) filter mixture . The sand won’t fit through the tiny holes in the filter paper so they’ll collect on paper but the salt will pass through the filter paper as its part of the solution
4) evaporate water from salt so that it forms dry crystals.