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The physical separation of substances - 2008chemistry11 - home - PowerPoint by 15YZi9l7

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									   The Physical Separation of
         Substances

    Filtration       •        Distillation
 Hand Separation     •        Evaporation
Solvent Extraction •        Recrystallization
Gravity Separation • Paper Chromatography
 By: Allan Y, Pauline W, Alex W, and Justus S
               Filtration
Allows for the separation of liquids from
solids
Usually involves a liquid (filtrate) that is
passed through a filter; the material that
remains on the filter is called the residue
              Filtration
Filtration cannot be used to separate
dissolved solids from a liquid (filtration
only works when the solid particles are big
enough to be seen)
                Distillation
As a liquid with the lowest boiling temperature
in the solution boils first, the vapor produced
ascends to the top of the distillation flask, passes
a thermometer, and enters the side-arm of the
flask which leads to the condenser. As the vapor
enters the cold inner surface of the condenser, the
gas cools and condenses back into a liquid,
which drips out the end of the condenser as the
distillate
Hand Separation
         Separation of
          MECHANICAL
          MIXTURES
         Can often be separated
          by HAND or by use of
          SIEVE or MAGNET
           Evaporation
 Separation of SOLID-IN-LIQUID
  SOLUTIONS
 Can often be separated by allowing liquid to
  EVAPORATE or to be BOILED AWAY,
  leaving solid
SOLVENT EXTRACTION
There are two ways in which this
   technique can be used …
                 # 1…
 Extraction of a solid from a mechanical
  mixture
 This method requires a liquid that
  dissolves one or more solids present so
  the desired product is left behind or
  dissolved and separated by evaporation
                  #2 …
 Extraction of a dissolved liquid or solid
  from a liquid solution
 To carry out this technique, a solution
  with one or more solid and/or liquid
  substances dissolved in a liquid solution,
  a solvent must contain two properties:
 The added solvent is immiscible with the
  solvent present
 The added solvent dissolves one or more
  desired substances from the substances and
  leaves behind the unwanted
 After the solvent is added, the mixture is mixed
  in a separatory funnel and the added solvent is
  drained from the original solvent
RECRYSTYALLIZATION
 Recrystallization is a variation of
  evaporation in which a solid in a solid-in-
  liquid solution is separated in a pure
  crystalline state
 A saturated solution must be prepared in
  order for recrystallization to occur
 A solid is added to a solvent until no more
  solid can dissolve and adding just enough
  hot solvent to dissolve the solid, the mixture
  is allowed to cool and evaporate, forming
  crystals
   Once the crystals have formed, they are
    removed by either hand separation or
    filtration
         Gravity Separation
 Separation of two components of a
  homogeneous mixture
 Clarification and thickening are two
  different products from the same method
 Method: in a mix of a solid and liquid, the
  solid will gradually gather at the bottom of
  the container while the liquid remains on
  top
        Gravity Separation
 Clarification wishes the purified liquid at
  the end
 Thickening wishes the purified solid at the
  end
 When feasible, centrifugal force may also
  be used in place of gravity (faster
  separation due to higher pressure upon
  contents)
     Paper Chromatography
 Separates small amounts of Solid-in-Liquid
  solutions containing two or more dissolved
  solids
 It requires a drop of the mixture placed near
  the end of a sheet of absorbent paper
 That end is dipped in the “developing”
  mixture
     Paper Chromatography
 As the solvent gradually travels up the sheet
  it will carry along the dissolved solids
 The edge of the solvent’s travels is known
  as the “solvent front”
 Depending on how readily the solids are
  dissolved by the solvent, various streaks of
  color will appear behind the solvent front
The END!!!!!!!!

								
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