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Choosing a solvent

  1. Nov 22, 2007 #1
    Here is the question I have, any help would be greatly appreciated.

    Which of the following organic solvents could be used to extract a neutral organic compound from an aqueous solution?
    ethyl acetate;
    ethanol;
    dichloromethane;
    hexane;
    acetic acid.
     
  2. jcsd
  3. Nov 22, 2007 #2
    If with "neutral" you mean "non polar" then you have to choose the less polar of the solvents, that is hexane.
     
  4. Nov 22, 2007 #3
    Thanks. I guess that is what was meant by neutral, I can't be certain as I gave you the exact wording of the question so that's all there is to go on.
     
  5. Nov 22, 2007 #4

    ShawnD

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    Dichloromethane is a good answer too since it settles to the bottom. You could extract the organic pieces without having to remove the water first.
     
  6. Nov 22, 2007 #5
    I vote for dichloromethane too, polar enough to get good mixing with the water, organic enough to extract the organic compound, density is great for easy separation.
     
  7. Nov 22, 2007 #6

    symbolipoint

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    Quick best guess is all of those except acetic acid. Better guess, maybe all except exclude acetic acid and exclude ethanol. Do you mean "neutral" in relation to acidic or alkaline; or do you really mean nonpolar?
     
  8. Nov 22, 2007 #7

    ShawnD

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    Acetic acid and ethanol would be terrible choices because they completely mix with water. It would either create one big phase, or it would have little separation. Ethyl acetate would probably work, but it's not the best choice because the density is somewhat close to water; it's about 0.9. Dichloromethane is very heavy at around 1.3, and hexane is very light at maybe 0.7

    If you're allowed to pick more than 1, I would pick DCM, hexane, and ethyl acetate.
     
    Last edited: Nov 22, 2007
  9. Nov 22, 2007 #8

    symbolipoint

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    Good Points. I did not think very clearly when I made my comment. I had imagined a mixture straight from solid phase; not exactly what many people have available once they are ready to use a solvent for extraction. Not all extractions are performed directly upon a liquid solution.
     
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