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### Topic: degree of ionization  (Read 15765 times)

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#### profmsg

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##### degree of ionization
« on: December 28, 2006, 03:10:19 PM »
hey
anybody know how to calculate the degree of ionization at pka 3 and ph 4

#### Borek

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##### Re: degree of ionization
« Reply #1 on: December 28, 2006, 03:16:59 PM »

Calculate pH, assume [A-] = [H+] and use degree of dissociation definition.
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#### profmsg

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##### Re: degree of ionization
« Reply #2 on: December 28, 2006, 03:21:48 PM »
can u calculate the degree of ionization of codeine at pka8.2 in the solution of ph 2

#### Borek

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##### Re: degree of ionization
« Reply #3 on: December 28, 2006, 03:44:36 PM »
Stop. That's what happens when you do three things at the same time. pH is given. Will take a look later.

Edit: OK. Find A/HA ratio from dissociation constant definition, express ionization degree with A and HA, then you need some simple math to get rid of A and HA (only their ratio is present in the final expression).
« Last Edit: December 28, 2006, 03:51:43 PM by Borek »
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#### chiralic

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##### Re: degree of ionization
« Reply #4 on: December 29, 2006, 07:20:53 AM »

http://www.raell.demon.co.uk/chem/logp/logppka.htm (check section 1.4 pKa or dissociation constant)

Regards,

Chiralic

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