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Seperation Techniques - Coggle Diagram

- - - - Separating funnel
        
        Complete separation can be achieved by sacrificing the liquids at the interface.
        
        With careful control, different portions of liquid can be drained off.
    - - Use magnet
        
        Application: Separating a mixture of different materials at a recycling plant.
        
        This process is limited to magnetic materials that can be attracted to a magnet.
        
        E.g. to separate iron fillings from a mixture of iron and sand.
    - - Filtration (insoluble solid as residue and solution as filtrate)
        
        With the help of a suitable solvent, filtration can be used to separate and purify substances.
        
        Small solvent particles pass through the filter paper and become filtrate.
        
        Filtrate - liquid which has passed through the filter paper
        
        Large insoluble particles are trapped by the filter paper and remain as residue
        
        Residue - particles that remain on the filter paper
        
        Application: In water treatment plants in Singapore, water is filtered through sand filters to remove insoluble substances.
  - - - E.g. protein. A chemical can be sprayed on the chromatogram to make the colourless spots visible. This liquid is known as a locating agent.
        
        Only "locating agent" is correct.
  - - - Evaporation to dryness
        
        Application : To make table salt from seawater.
        
        The soluble solid can be separated from its solution by evaporating the solvent away by heating.
        
        The solvent is usually sacrificed.
        
        This method is not used to recover solutes that are easily damage/decomposed by heating.
        
        E.g. sugar decomposes during heating.
      - Crystallization (for substances that decompose on heating)
        
        Evaporates off some of the solvent to obtain a saturated solution.
        
        Saturated solution - A solution that contains the maximum amount of solute in a given volume of solvent at a fixed temperature.
        
        It will not dissolve any more solute at a particular temperature.
        
        The soluble solid is separated as crystals formed from the saturated solution. This is achieved by cooling the saturated solution.
        
        Application: Sugar can be produced by crystallization of sugar from sugar cane juice.
    - - Simple
        distillation
        
        The solvent vapour is cooled down and condensed in a Liebig condenser. The liquid obtained is known as distillate.
        
        In Liebig condenser, water must enter from the bottom to ensure that:
        
        The coldest part of the condenser is just before the vapour escape.
        
        The entire jacket is filled with water.
        = More effective cooling is achieved.
        
        Boiling chips are added into the distilling flask to ensure smooth boiling.
        
        The solution is heated to boil off the solvent.
        
        Thermometer is placed with its bulb at the inlet of the condenser to measure the temperature of the vapour entering the condenser.
        
        Application: Pure water can be obtained from sea
        water by distillation.
    - - Fractional distillation (separated by difference in boiling points)
        
        Applications
        
        Fractional distillation of liquid air to obtain gases like oxygen and nitrogen.
        
        Refining crude oil to obtain useful products like petrol and kerosene.
        
        A fractionating column is packed with glass beads or some unreactive substance.
        
        Increases surface area for vapour to condense
        
        Ensures that components with different boiling point will leave the column at different time.
        
        Apparatus used is the same as that for simple distillation, except for the addition of a fractionating column.
        
        The components must have different boiling
        points.
        
        Liquid with the lowest boiling point will be distilled
        over first.