mycotheologist
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How to titrate an acid dissolved in acetic acid
I made a solution of HCl in glacial acetic acid and I'm trying to figure out how to determine the exact concentration of HCl in the CH3COOH. At first
I thought of using an extremely weak base that can only be protonated by the HCl but that wouldn't work because the end point could never be reached
considering the solution would remain acidic due to the acetic acid.
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Paddywhacker
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See this thread.
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Poppy
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I would strongly suggest a fisherman's pH meter. It works much better. Adding loads of electrolytes makes the pH measure innacacurate. Hopefully that
i'll make you to the point. Lol.
[Edited on 6-27-2012 by Poppy]
[Edited on 6-27-2012 by Poppy]
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blogfast25
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That thread isn't about GLACIAL acetic acid as a solvent.
Quite a bit of information can be gleaned from the relevant Wiki entry:
http://en.wikipedia.org/wiki/Nonaqueous_titration
Titration of a very weak base like pyridine (in GAA) with a solution of perchloric acid (in GAA) appears possible. Perhaps titration of HCl (in GAA)
with pyridine (in GAA) is also possible?
[Edited on 27-6-2012 by blogfast25]
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weiming1998
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I would suggest redox titration. Add KMnO4 or MnO2 to your HCl/acetic acid. Chlorine gas and crystals of MnCl2 would form. When the solution turns
purple (KMnO4) or the MnO2 stops dissolving, the titration is over. Acetic acid does not react with KMnO4 under normal conditions.
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blogfast25
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Quote: Originally posted by weiming1998  | | I would suggest redox titration. Add KMnO4 or MnO2 to your HCl/acetic acid. Chlorine gas and crystals of MnCl2 would form. When the solution turns
purple (KMnO4) or the MnO2 stops dissolving, the titration is over. Acetic acid does not react with KMnO4 under normal conditions.
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That's not a bad idea, weiming. Dilute the GAA/HCl solution a bit first and that probably should work.
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unionised
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Argentimetry?
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blogfast25
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Yep. Bit expensive...
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unionised
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Silver is recyclable.
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blogfast25
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But you have to have some to begin with... 
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DJF90
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Its also not THAT expensive. I've just bought 10g for about £8. Can't complain, and it'll suffice my analytical needs.
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Hexavalent
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I got about 4g for free from school: they had demonstrated the silver nitrate/copper reaction several times and were just going to throw out the
silver produced, so I turned up with my vial and salvaged it.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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blogfast25
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| Quote: Originally posted by DJF90 | | Its also not THAT expensive. I've just bought 10g for about £8. Can't complain, and it'll suffice my analytical needs. |
I just bought some myself, about the same price. Bit of a battle to get it at the right price, though...
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weiming1998
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Not to mention that any additional chloride ions will mess up the result, plus the nitric acid produced might redissolve the AgCl precipitate at high
enough concentration, unless the Ag+ ion is in the form of silver acetate.
But then again, my idea of redox titration wouldn't be good if there are reducing contaminants (like ethanol) in the glacial acetic acid. Perhaps I
could ask the original poster whether the GAA is home-made or lab grade?
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