Solubility & pKa: Intuitively Determine Compound Dissolution?

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SUMMARY

This discussion focuses on the relationship between solubility and pKa values in determining the dissolution of organic compounds. It highlights that a compound with a low pKa, such as H2SO4 (pKa ~ -4), will dissolve a compound with a higher pKa, like an ester (pKa ~ 25), while it will not dissolve in NaOH (pKa ~ 40) or water (pKa ~ 15). The conversation emphasizes the importance of understanding ionization constants (Ka) and their relation to pKa in predicting solubility behavior without relying solely on memorization of solubility rules.

PREREQUISITES
  • Understanding of pKa and Ka values in acid-base chemistry
  • Familiarity with organic compound classifications, specifically esters
  • Knowledge of solubility principles in aqueous solutions
  • Basic grasp of acid-base reactions and their equilibrium
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  • Research the relationship between pKa and solubility in organic solvents
  • Study the principles of acid-base reactions and their impact on solubility
  • Explore the concept of ionization constants (Ka) in various solvents
  • Learn about the solubility of different functional groups in organic chemistry
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Chemistry students, organic chemists, and anyone interested in understanding the solubility of organic compounds based on pKa values.

thunderfvck
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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.
 
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Bath time --- sorry, a single, general rule would be too nice for mother nature to tolerate.
 
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.

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