May 15, 2024, 08:24:40 PM
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Topic: How does a person determine the degree of deprotonation between an acid/base?  (Read 3512 times)

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Offline Zensation

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If the pKa's are known, how does one determine the degree of deprotonation?

For example, the Sodium enolate salt can be isolated from an active methylene compound with a pKa of 9.5 by reaction with NaOH. Yet, in a reaction involving this enolate, there are indications of base disassociation by evidence of side reaction products. This would seem to indicate that deprotonation was not 100%, yet, was largely to the right.

Is there some sort of rule/calculation a person can use to determine the degree of deprotonation that has taken place?

Offline zsinger

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Yep.  Called Percent Ionization :).  Its a Chemistry 2 Concept.
              -Zack
"The answer is of zero significance if one cannot distinctly arrive at said place with an explanation"

Offline Zensation

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Thanks!

I was looking into this concept. It seems you can only calculate it based off known levels of ionized acid, before and after, in the solution?

Is it possible to calculate theoretical percent ionization based off of known pKa and pKb values?

Offline kriggy

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yes, you can calculate α which is degree of dissociation and c is concentration. K is dissociation constant of given acid/base
K=α2*c /1-α

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