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Purification Techniques CHEM241-07A, immiscible with first solvent (water)…

- - - - used when neither compound is significantly more volatile than the other (their boiling points differ by less than 30 degrees)
        
        Pros:
        
        Distillation proceeds quickly
        
        Can be conducted without a fractionating column
        
        Cons:
        
        Can’t be used when compounds’ boiling points are relatively similar
    - - used when one compound in a solution is a lot more volatile (their boiling points differ by over 100 degrees) than the other compound
        
        Pros:
        
        Can be used even when compounds’ boiling points are relatively similar
        
        Can separate mixtures of liquids
        
        Cons:
        
        Distillation occurs more slowly
        
        Needs fractionating column
    - - A compound is heated with a sand bath and the vapors that are produced from the heating are cooled using a condenser and collected. Fractional distillation adds a fractionating column with metal turnings that adds “theoretical plates” to produce multiple condensation-vaporization steps and more efficiently separate the compounds
        
        https://www.youtube.com/watch?v=eQlnHr9g6Io&ab_channel=Cognito
    - - It is appropriate to use distillation on liquids, as the vaporization of the liquids and then condensation produces the product yield. This technique should be used with mixtures, as its main purpose is to separate mixtures or solutions of two compounds.
- - - - Partitioning (separating) a mixture of components into one of two immiscible solvents based on the preferential solubility of the various components
        
        Macroscale Extraction
        
        The two solvents and the mixture to be separated are placed in a piece of glassware called a separatory funnel and shaken. Shaking thoroughly mixes the layers and allows the solutes to partition into their preferred layer. The immiscible solvents are allowed to separate, then they are drained one at a time. This is repeated as needed with various solvents until the mixture is sufficiently purified.
        
        Start with the stop cock at the bottom in a closed position.
        
        Add liquids through the top (aqueous is more dense, organic less dense), stopper the funnel, and secure it with your fingers on both sides.
        3.Shake this with the funnel inverted and release some pressure until there is no longer evidence of gas releasing.
        
        The funnel is set in the iron ring and the stopper removed immediately.
        
        Once the contents settle, 2 layers will form.
        
        The lower layer is transferred into a beaker with the funnel touching the side and leaving 2 drops in the funnel.
        
        Moves compounds from one liquid to another so they can be more easily manipulated or concentrated
        
        Eenables selective removal of components in a mixture
        
        Involves no evaporation (carried out at mostly ambient temperatures, can be used for high temperature sensitive products)
        
        More cost effective than some other methods
        
        Solvent may dissolve unwanted products (possibility of low recoveries)
        
        Emulsion (suspension of microscopic liquid drops within another liquid) may occur so gently swirl instead of shake possible.
        
        https://www.youtube.com/watch?v=N96JaRnE7n0
        
        Microscale Extraction
        
        Use plastic centrifuge tubes (calibrated) or a reaction tube.
        
        It should have a screw cap and tapered end (helps separate lower end more efficiently).
        
        The tube should be shook and held upside down.
        
        After the liquid separates into 2 distinct layers a dropper is used to transfer the upper layer.
        
        Using smaller volumes can be more effective
        
        Solvent may dissolve unwanted products (possibility of low recoveries)
        
        Emulsion (suspension of microscopic liquid drops within another liquid) may occur so gently swirl instead of shake possible.
        
        https://www.youtube.com/watch?v=E33gCnnsOmM
- - - - Alumina can be used
    - - Hexane can be used
        
        Organic Solvent
    - - There is a wide variety of mixtures that can be used
      - The components can be reused for other processes after column chromatography separates
      - There is a wide variety of stationary and mobile phases to separate various mixtures
    - - A high quantity of solvents is required for a successful column chromatography
      - Column chromatography takes a significant amount of time
      - It has a lower separation power than other processes
      - Errors are common
        
        Can be from overloading the column
        
        Other errors during loading period
    - - Prepare Sample
        
        Pack Column
        
        Load Column/Add Sample
        
        Elution & Flash Chromatography
      - https://www.youtube.com/watch?v=UmWMlKJAdSk
- - - - Choose solvent
      - Dissolve solute by Heat
      - Rapid Filtration to remove impurities
      - Crystallize the hot saturated solution
      - Filter the crystals
      - Air dry
      - Weigh the final product
      - (https://www.youtube.com/watch?v=ohtrnIODkAM)
    - - Cons:
        
        -Purifies only 1 compound at a time
        
        -Yield is limited due to phase equilibria
        
        -Process kinetics are more complex meaning obtaining detailed kinetic parameters involves complex experimental procedures
        
        -Liquids may need to be purified for further use
      - Pros:
        
        -High purification can be obtained in a single step
        
        -Produces a solid phase which may be suitable to for direct weighing of the substance
        
        -Operates at a lower temperature than distillation separation
    - - You want to use crystallization when you have an impure, solid compound and you want to rid the compound of impurities
      - In order to rid the compound of impurities, you must go through the recrystallization process to ensure that the impurities are removed and you are left with your pure substance
      - More times than not, the recrystallization process is done at a slow pace, but done in one step to ensure that the impurities are removed properly