theory and acetate

Randall J. Cohrs COHRS-R at Oberon.HSC.Colorado.edu
Fri Nov 11 15:58:04 EST 1994


> In article <39qfo2$m9t at unicorn.ccc.nottingham.ac.uk>,
> Simon Dawson  <mbxspd at unicorn.nott.ac.uk> wrote:
> >Ok....an answer to the 2M NaOAc pH4...maybe. We have had the same
> >problem. Pain in the *** isn't it? The way we do it now is...say we
> 
> 
> Actually, the answer is quite easy.  Make up some 2M NaOAc.  Make up some
> 2M Glacial acetic acid.  Mix until you get the right pH.  Somewhere you
> should be able to find the buffer table that tells you how much of each
> to add, or you can derive it theoretically, or you can figure it out
> empirically.
> 
> Carlisle Landel
> 
> PS  I have a *very* foggy recollection that the ration is something like
> 8:2, acid to salt, but I could very well be wrong.
> 
> 
 - - -

If Henderson-Hasselbalch is correct and 
pKa of acetic acid is 4.76

then

0.585 M acetic acid + 1.415 M sodium acetate is what you want

rjc in denver




More information about the Methods mailing list