Separating Mixtures

1
Separating Mixtures
2
How do we separate ?
3

• Filtration
• Chromatography
• Centrifuging
• Evaporating
• Crystallisation
• Dissolving
• Decantation
• Sieving
• Flotation
• Sedimentation

4
Filtration - The process whereby fluids pass
through a filter or a filtering medium. A process
like sieving, where large particles are caught on
filter paper, whilst solutions pass through
5
(No Transcript)
6

• Centrifuges rotate containers of
• liquids to separate suspended
• materials with different densities.
• Centrifuges separate different components of
  human blood or milk and to clarify solutions. A
  high speed separator can rotate at great speed to
  separate fat (cream) from milk.
• The spin drier in washing machines is a type of
  centrifuge that throws out the liquid by the
  "centrifugal force" of the rotation.

7
http//www.rocketguy.com/rocket/cent_trial.html
8
Centrifuging
9
Decantation
10
Evaporation changes state from a liquid to a gas.
Evaporation occurs only from the surface of the
liquid.
11
(No Transcript)
12
Crystallization refers to the formation of solid
crystals from a homogeneous solution.  It is
essentially a solid-liquid separation technique.
13
Crystal a solid in which the atoms, molecules
or ions are packed in a regular, ordered,
repeated pattern.
Examples salt, sugar, baking soda, baking
powder, quartz, diamonds,
14
Copper Sulphate Crystals
15

• Distillation is a method used to separate a
  liquid from a solution through boiling and
  condensation

Rose oil distillation
16
(No Transcript)
17
Separating funnel
18
Fractional Distillation
19

• Chromatography ( colour writing) is used to
  separate small amounts of chemicals so that they
  can be analysed.
• Different substances or different components move
  at different speeds through a strip of wet paper
  a gel or a gas.

20
EXTRACTING OIL FROM NUTS.1 Place ground peanuts
into a mortar. 2 Add 20 mL of methylated
spirits. 3 Thoroughly grind nuts in solvent. 4
Pour liquid into a test-tube5 Filter into an
evaporating basin. 6 Warm evaporating basin for
10 minutes. 7 The solvent evaporates leaving the
oil extracted from the nuts.