Polverone
Now celebrating 21 years of madness
Posts: 3186
Registered: 19-5-2002
Location: The Sunny Pacific Northwest
Member Is Offline
Mood: Waiting for spring
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document "formic acid to formaldehyde" in error?
The Royal Society of Chemistry journal archives went online recently, and I've been browsing them. My school hasn't yet subscribed, but the
abstract articles can be pretty detailed and are free to all. In any case, in more than one of these articles I read that the pyrolysis of calcium
formate yields mostly methanol, with a relatively small amount of formaldehyde mixed in. Maybe this is simply a matter of varying experimental
conditions, but still I found it discouraging from a preparative standpoint. All in all, it makes me wonder if I should leave the document, remove it,
edit it, or reassess what the Library is and what it should be.
I'm still trying to figure out where I should go with the library. It would be nice to have an organized collection of preparations,
demonstrations, and student-type investigations. But right now all it has is a few miscellaneous articles and a section that will soon be flooded with
archaic books.
I like the idea that especially good posts or threads from the forum would be edited and turned into Library documents, but there's always
something more pressing or interesting to take care of.
PGP Key and corresponding e-mail address
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Ramiel
Vicious like a ferret
Posts: 484
Registered: 19-8-2002
Location: Room at the Back, Australia
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Mood: Semi-demented
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I think when I suggested the idea I siad I'd help to make it a reality. Just tell me what to summarise, aim and fire.
I'll put it in the same formatt as the other stuff I've submitted, just to be consisitent.
Sincerely
-Ramiel
Caveat Orator
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BromicAcid
International Hazard
Posts: 3246
Registered: 13-7-2003
Location: Wisconsin
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Mood: Rock n' Roll
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.....reassess what the Library is and what it should be.
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One thing that I've always wanted to see in the library are basically journals. From the people here.
For example, I've been keeping a written account of my attempts to make phosphorus, in it I have detailed descriptions of what I saw when certain
reactions took place, what the results were, and what conclusions I came to alone with warnings. Then in subsequent writings to the document I
changed things and it evolved. It should be completed this summer when I add the last two sections that I want to do, one 'perfected'
version of the reduction of phosphates with an active metal, and one on the reduction of lead phosphate with hydrogen at 200C.
I just like to read what the people think about their reactions and their responses to them, not only are they interesting but you can learn a lot
about what you really should expect from a reaction and you can choose modifications from what the people before you did. Basically anything that
someone has tried at through several runs, like sodium production, or hydrazine, or some nitrations, how their procedures changed, that's one
thing I would like to see there.
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trilobite
Hazard to Others
Posts: 152
Registered: 25-2-2004
Location: The Palaeozoic Ocean
Member Is Offline
Mood: lonely
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Formic acid to formaldehyde
Polverone: According to US915946 that method for formaldehyde production can be get to work if the formaldehyde formed is sweeped from the reaction
chamber with a carrier gas before it gets decomposed. Not an easy reaction I guess.
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madscientist
National Hazard
Posts: 962
Registered: 19-5-2002
Location: American Midwest
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Mood: pyrophoric
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I thought thermal decomposition of calcium formate yielded formaldehyde and no methanol. I don't see how it possibly could yield any methanol.
I weep at the sight of flaming acetic anhydride.
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Turel
Hazard to Others
Posts: 141
Registered: 29-11-2003
Location: The Hardware/Software Interface
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Mood: Thixotropic
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Formate Ion
Both are very possible and likely. Formate ion is a good reducing agent for carbonyl bonds. If formaldehyde was present through a reaction, it is very
possible that formate ion reduces formaldehyde to methanol, itself becoming carbon dioxide. These type of auto-redox reactions are common with
aldehydes and formic acid.
[Edited on 21-5-2004 by Turel]
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PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
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Mood: Bis-diazo-dinitro-hydroquinonic
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Formaldehyde is one of the most reactive aldehydes and it displays very strong reduction abilities....
Cannizaro's reaction works quite wel with bases...maybe that at the temperature of reaction...the CaCO3 suface is basic enough to help further
oxydoredox...
Ca(O2CH)2 --> CaCO3 + CH2=O
CH2=O + CH2=O -base/heat/H2O-> CH3-OH + HCO2H
But in this case there is no water since water is forbiden in this reaction (formate must be very dry and anhydrous)...This will mean heat was too
strong and CH2=O turns into CO2 to give all its H to the other CH2=O to form CH3-OH
The use of formate to make CH2=O is a waste of valuable formate since CH2=O can be made quite eqsyly from more available CH3-OH upon metal catalyst or
with comon oxydisers.
Formate must be used to get the more valuable aldehyds of higher alkylic chain.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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