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Topic: Theoretical titration of an amino acid  (Read 3863 times)

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lifesayko

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Theoretical titration of an amino acid
« on: April 22, 2006, 12:11:05 PM »
Hi,
We recently did the titration of amino acids, and covered such things as the zwitter ion etc., and I understand these concepts, and I can identify them in a graph, but..
I was given theoretical solution of alanine, (100% protonated), and told to calculate the pH at various steps during titration. At the very beginning, I suppose I simply consider COOH as an acid, but as I approach the zwitter ion state, don't I need to consider both acids? How do I calculate that?

thanks in advance

Offline Mitch

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Re: Theoretical titration of an amino acid
« Reply #1 on: April 22, 2006, 08:12:39 PM »
Can't you look up the pKa?
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Offline Equi

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Re: Theoretical titration of an amino acid
« Reply #2 on: April 23, 2006, 03:54:07 AM »
Can't you look up the pKa?
exactly, take a look at the Henderson-Hasselbalch equation.
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