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Solubilities and pKa

  1. Dec 19, 2003 #1
    Yes. Hello. I am new. THis is a nice forum. Very nice website. Wish I would have found it sooner.

    Okay, my question.
    Without having to rely on memorizing solubility rules (specifically for organic compounds), is there a intuitive way to determine what will dissolve in what based on the relative pKa's of solvent/solute? eg. a compound dissolves in H2SO4(pKa~-4), but not in NaOH(~40) or H20(~15). The compound is an ester (~25). Help? Or shall I have a nice warm bath with some MEMORIZING bubbles...!?

    ....mesmerizing...memorizing. Ahh...7 am and I still got it.
  2. jcsd
  3. Dec 19, 2003 #2


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    Bath time --- sorry, a single, general rule would be too nice for mother nature to tolerate.
  4. Dec 19, 2003 #3


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    There is a distinction between dissolving and ionization constants, for example when you are talking about a salt dissolving in water yet not leading to a change in pH. That is dissolving usually is relevant to water.

    As you may know by now Pka is related to Ka which is the ionization constant commonly used for Arrehnius acids. Ka has to do with the equilibrium concentration of hydrogen ions. In this sense a base will have a high Pka. Thus in general you can say that a compound with a very low pKa will react with one with a high pKa since this is referring to a strong acid/base reaction.

    General Chemistry Homework
    http://groups.msn.com/GeneralChemistryHomework [Broken]

    Last edited by a moderator: May 1, 2017
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