April 13, 2021, 02:58:15 AM
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Topic: Buffer Question  (Read 164 times)

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Offline prague441

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Buffer Question
« on: March 11, 2021, 05:41:14 AM »
The pKas citric acid are pK1 = 3.1, pK2 = 4.1, pK3 = 6.4. You were tasked to prepare 1L of a 0.5 M of citrate buffer at pH 4.0. The problem is, only solid trisodium citrate is present in the lab stockroom. How will you prepare the buffer then?

Offline chenbeier

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Re: Buffer Question
« Reply #1 on: March 11, 2021, 07:01:42 AM »
In this case you cannot make a clean buffer. You have to add some other acid to convert the trisodiumsalt to Di or Monosodiumsalt so it fits to the Henderson  Hasselbalch  equation.
Probably HCl or H2SO4 can be used if chloride or sulfate will not disturb.

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