chapter 4 exploring diversity of matter through separation techniques)

Question 1

filtration

Answer 1

• used to separate an insoluble solid from a liquid
• the filtered insoluble solid is collected in the filter paper and is referred to as residue
• the liquid that passes through is referred to as the filtrate

Question 2

evaporation [to dryness]

Answer 2

• obtains a soluble solid by heating a solution
  [but not all solids can be obtain by evaporation]
  [solids may also be impure because any soluble impurities in the solution would be left together with the end product]

Question 3

[simple] distillation

Answer 3

• used to separate a pure solvent from a solution
  distillation apparatus/ set-up
• thermometer : measures temp. of evaporated water
• boiling chips : ensures smooth boiling
• solution is evaporated into water vapour, which is then cooled and turned into pure liquid [referred to as distillate]

Question 4

[paper] chromatography

Answer 4

• used to separate 2 or more components that dissolve in the same solvent [e.g. pigments in plants and dyes in paints]
• the solubility of a component determines the travelled distance on the chromatogram