Sciencemadness Discussion Board

Preparation paraformaldehyde

Filemon - 8-7-2007 at 09:51

I have tried to synthesize paraformaldehyde with Methanol + NaOCl + HCl. The HCl I have used it to accelerate the decomposition of NaOCl. But the bubbles (hydrogenate?) that have seen they suggest that it has taken place colateral reactions. What reaction does it take place in a half sour one? As I can identify if it is paraformaldehyde?

garage chemist - 8-7-2007 at 12:25

How is that supposed to work? You'll only get CO2 as an oxidation product, since formaldehyde and formic acid are stronger reducing agents than methanol and are more likely to be oxidised by NaOCl than the methanol.
Also, even if it did work you'd only obtain a very dilute solution of formaldehyde, never paraformaldehyde.

Paraformaldehyde is obtained by distilling the water out of strong formaldehyde solutions in vacuum.
Formaldehyde is made by dehydrogenating or oxidising methanol in a catalyst tube at elevated temperature, like acetaldehyde is made.
Formaldehyde or paraformaldehyde isnt something you can simply synthesize in a lab. You buy it.

[Edited on 8-7-2007 by garage chemist]

Filemon - 8-7-2007 at 12:47

Quote:
Originally posted by garage chemist
How is that supposed to work?
[Edited on 8-7-2007 by garage chemist]


CH3OH + Cl2 => CH2ClOH + HCl

The CH2ClOH are unstable and it decompose in CH2O + HCl

garage chemist - 8-7-2007 at 12:51

I already explained to you that it does not work like that. Formaldehyde is not a laboratory preparation.

franklyn - 10-7-2007 at 08:52

An alternative _
http://www.sciencemadness.org/talk/viewthread.php?tid=8337&a...

.

Alexchimiste - 15-7-2007 at 04:56

Formaldehyde solutions gives a precipitate of paraformaldehyde when they are at light stored ...

Aqua_Fortis_100% - 16-7-2007 at 03:52

AFAIK , adding sulfuric acid to common 37% formadehyde, also ppt te paraformaldehyde, but this will be very impure and need of a way to purify (i cann`t remember now how).

have anyone tried this?