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Topic: pH of KPi buffer  (Read 12021 times)

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Offline enahs

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pH of KPi buffer
« on: October 02, 2008, 08:39:48 PM »
Ok, I had to calculate this today at work and thought it might make a good little question. It has been so long since I have done any serious pH calculations I am ashamed it took me longer then it should have  >:(.

What is the final pH if you add 0.25μL of 1M Perchloric Acid to 0.75μL of a solution buffered to pH 7.4 with "50 mM Potassium Phosphate" buffer?


Offline AWK

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Re: pH of KPi buffer
« Reply #1 on: October 03, 2008, 01:15:15 AM »
Hint
Stronger acid replaces the weaker
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Offline Borek

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Re: pH of KPi buffer
« Reply #2 on: October 03, 2008, 04:15:59 AM »
That, plus stoichiometry and Henderson-Hasselbalch.
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Offline AWK

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Re: pH of KPi buffer
« Reply #3 on: October 03, 2008, 04:42:07 AM »
This is an excess of HClO4!
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Offline Borek

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Re: pH of KPi buffer
« Reply #4 on: October 03, 2008, 05:02:14 AM »
Yes, overlooked that.

Still, that will be obvious after stoichiometry step.
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