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Separating mixtures (solid mixtures (Crystallisation (differences between…

- - - - Examples:
        -water and sand
        -chalk powder and water
        
        Residue=sand
        Filtrate=water
        
        Residue=chalk powder
        Filtrate=water
  - - - At the scrapyard, cranes with electromagnets separate magnetic metals from non-magnetic materials.
  - - - Evaporation involves heating the solution to dryness.
      - On the other hand, crystallisation involves heating the solution until you obtain a saturated solution.
      - Processes
        
        Process 2: cooling
        
        Process 1: heating
  - - - Example:
        iodine solid and sand
        ammonium chloride mixture
        
        Heating followed by sublimation and deposition
- - - - Used to separate miscible (dissolved) liquid mixtures that have different boiling points
        
        Same as simple distillation but.....
        
        Longer because the liquid with lower boiling
        point boils first and collected, followed by second liquid
        
        Procedure:
        
        Heating solution
        
        Liquid with lower boiling point boils first and is later collected after condensation through condenser
        
        Liquid with higher boiling point will boil later and after condensation, is collected as a liquid in a separate flask
        
        A fractionating column is used in the process.
        When both vapours rise up the column, the liquid with a higher boiling point is separated from the liquid with a lower boiling point.
        The higher boiling point liquid condenses and falls back into the boiling flask.
  - - - Apparatus (important): a condenser
        
        The condenser is used to cool down the vapour into a pure liquid (distillate).
        
        Another important apparatus is the thermometer.
        
        The thermometer is placed usually at the mouth of the condenser. It measures the boiling point of the liquid.
  - - - Used to determine the contents of pen ink to determine if the signature is forged or not.
      - Used to test athletes’ urine samples to find out if they used performance enhancing drugs in their event, if positive, disqualified.
      - Procedure:
        
        Draw a line using pencil on the chromatogram paper.
        
        Put a dye on the line above the solvent
        
        Close the lid immediately
        
        The Rf value is used to compare the solubility of different substances in the dye
        
        It is the ratio between the distance traveled by the substance and the distance traveled by the solvent is a constant (c).
        This ratio is called the Rf value.
        
        If the chromatogram shows only one spot, the substance is pure, therefore, the purity of the substance is 100%
  - - - Water and oil
        
        Procedure:
        1.Two liquids allowed to separate from each other (oil floating above water)
        
        Liquid below is poured and collected, followed by second one