DrNewbee
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Formic acid titration
Hi guys.
I was wondering if i could use the same technique for titration of formic acid to get to its concentration in % as i would Hydrogperoxide? Would i use
the same chemicals. ..pottasium permanganate and sulphuric acid?
Or should the sulphufric acid be changed with naoh or another base?
If it is not optimal could i by some way still do this?
Any tips are appreciated. ..
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gdflp
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The method that I believe you are thinking of utilizes the fact that hydrogen peroxide is an oxidizer, and thus the amount of oxygen produced can be
measured and a concentration determined. As formic acid is not oxidizing, this won't work.
The easiest way to titrate formic acid would be to measure out a known quantity of the acid, add several drops of a ~1% phenolphthalein solution and
slowly add a solution of a strong base, NaOH or KOH are best, until the solution turns a faint pink. Since formic acid is a monoprotic acid, you can
calculate the number of moles of base that were used to neutralize all of the formic acid and thus determine the number of moles of formic acid you
started with. Then divide this number by the volume of formic acid used in liters to get a concentration in molarity. If you want to know the
percent concentration, you will need to know the density of the formic acid. This is an acid-base titration, and is one of the most common and
easiest type of titration for beginners. The chemical equation is as follows : HCOOH + KOH --> KCOOH + H2O
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DrNewbee
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Quote: Originally posted by gdflp  | The method that I believe you are thinking of utilizes the fact that hydrogen peroxide is an oxidizer, and thus the amount of oxygen produced can be
measured and a concentration determined. As formic acid is not oxidizing, this won't work.
The easiest way to titrate formic acid would be to measure out a known quantity of the acid, add several drops of a ~1% phenolphthalein solution and
slowly add a solution of a strong base, NaOH or KOH are best, until the solution turns a faint pink. Since formic acid is a monoprotic acid, you can
calculate the number of moles of base that were used to neutralize all of the formic acid and thus determine the number of moles of formic acid you
started with. Then divide this number by the volume of formic acid used in liters to get a concentration in molarity. If you want to know the
percent concentration, you will need to know the density of the formic acid. This is an acid-base titration, and is one of the most common and
easiest type of titration for beginners. The chemical equation is as follows : HCOOH + KOH --> KCOOH + H2O |
Thanks man...i will dwelve in to the technique as soon as i can... by the way...if i made the formic acid with anhydrous glyserol and oxalic acid,
what concetration range are we talking...i mean it must have been calculated some time before...any thoughts?
By the way thanks for the quick response. .
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gdflp
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I looked and I couldn't find any data on the concentration of the formic acid. However, if you used anhydrous glycerol, I would expect a
concentration of at least 50%. It may be higher, it may be lower though, I'm not entirely sure.
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DrNewbee
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| Quote: Originally posted by gdflp | | I looked and I couldn't find any data on the concentration of the formic acid. However, if you used anhydrous glycerol, I would expect a
concentration of at least 50%. It may be higher, it may be lower though, I'm not entirely sure. |
Ok thanx much appreciated. ..i too have tried all sources for that... but one last thing...how do i practically increase the cocentration without
fhancy chemicals...i do have top notch glassware and most chemicals but not the unique once...
Thx again
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