Little_Ghost_again
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formic acid synths
Hi
I would like to make a small amount of formic acid by small I mean 100ml or less.
How do I hydrolise chloroform to make formic acid? And what other ways would make it.
Thanks for the help
LG
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Chemosynthesis
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Oxidation of methanol is probably the simplest OTC method.
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Little_Ghost_again
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Ok thanks. I will look into that. I want to compare with ant formic acid from my red and black ant farms
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HgDinis25
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Actualy, the best OTC method to produce small quantities of formic acid is the Glycerin - Oxalic Acid method:
http://www.erowid.org/archive/rhodium/chemistry/formic.acid....
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Amos
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I will second the oxalic acid method. I have tried and made a couple mL even with horrible 5% oxalic acid cleaner. The glycerol is recycled, too, so
even more convenient.
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HgDinis25
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I've done that reaction a few times and in all of them I was left with a viscous blackish liquid, probably glycerine with side products from the
various reactrions happening at the same time (AKA crap). I've never been able to recycle it.
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Texium
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I just finished making some formic acid using the glycerol and oxalic acid method. I started by refluxing a mixture of 28 mL of glycerol (it was all
that I had, I need to buy more) and 16 g of oxalic acid at about 100°C until CO2 evolution ceased. Then I set it up for simple
distillation and distilled the product, with the distillate coming over at around 100-110°C. My yield was 16 mL of crude formic acid, but I have not
yet titrated it to determine the concentration, and might not anyway since it's a quite small amount and I don't really need to know. It has a
terribly sharp and biting smell to it, intensely burning my eyes and nostrils if I do so little to disturb it as pouring some into another container.
Next time I make it (at the suggestion of plante1999 via Skype), I will neutralize the formic acid after the initial reflux step, and then distill
everything in the solution with a BP of less than 100°C to remove the allyl alcohol impurity that is formed in the reaction. This will be followed by
reacidifying the residual sodium formate solution and distilling the more pure formic acid.
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Loptr
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Quote: Originally posted by zts16  |
Next time I make it (at the suggestion of plante1999 via Skype), I will neutralize the formic acid after the initial reflux step, and then distill
everything in the solution with a BP of less than 100°C to remove the allyl alcohol impurity that is formed in the reaction. This will be followed by
reacidifying the residual sodium formate solution and distilling the more pure formic acid. |
I recall allyl alcohol being a lachrymator, so I can imagine the distillate being quite irritating! 
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Oscilllator
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| Quote: Originally posted by Loptr | | I recall allyl alcohol being a lachrymator, so I can imagine the distillate being quite irritating! |
Methinks this contributed to zts16's burning of the eyes and nostrils.
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Texium
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I think it must have, because I've
worked with pure 78% formic acid at school before, and while that definitely had an irritating odor, it was nowhere near as bad as the stuff that I
made yesterday. It caught me somewhat off guard, as I hadn't read previously that allyl alcohol was a lachrymator.
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