Separation techniques - filtration, crystallisation and evaporation

Question 1

what is filtration?

Answer 1

Filtration is a process used to separate insoluble solids from liquids by using a filter paper and funnel to filter out the solvent into the beaker

Question 2

what are the apparatus used in filtration?

Answer 2

filter paper
funnel
beaker

Question 3

how would you use filtration to separate sand from water?

Answer 3

The sand and water mixture is poured into a funnel lined with filter paper, and the filtrate is collected in a beaker below.
The residue, sand, remains on the filter paper and can be discarded.

Question 4

what is evaporation?

Answer 4

Evaporation is used to separate soluble solids from liquids by boiling it to certain temperatures

Question 5

how does it work?

Answer 5

at a certain temperature, a liquid will turn into a gas, leaving behind any solids that may have been dissolved in it. for example mixture of salt and water

Question 6

what are the apparatus used in ‘evaporation’?

Answer 6

evaporating dish
bunsen burner or water bath

Question 7

how would you use evaporation to separate salt from water?

Answer 7

pour the mixture into an evaporating dish
slowly heat it, the solvent will evaporate
keep heating it till all that are left are dry crystals

Question 8

what is crystallization?

Answer 8

Crystallization is a separation technique that is used to separate pure compounds from a solution that are temp - sensitive, i.e destroys in high tempeartures.

Question 9

how would you use crystallization to separate salt from water?

Answer 9

• pour the mixture into an evaporating dish
  and gently heat it,
• once some of the solvent has evaporated,
  remove the evaporating dish form the
  heat and leave to cool.
• the salt should start to form crystals
  filter out the crystals and leave to dry.