Organikum - 8-3-2004 at 12:04
German patent DE29771 from 1884 (yeah!)
Iodoform:
50kg KI are dissolved in about 300kg water and about 30kg alcohol (96%) are added. This solution is electrolysed "in the heat" whilst CO2 is
bubbled into the solution.
Iodoform precipates as crystalline powder.
REMARK: "In the heat" will probably say that the solution is to be heated - not more not less.
For the production of bromo or chloroform the correspondending halocompounds are electrolysed same as with happened iodoform but there is no CO2
bubbled into the solution.
REMARK: Thats all. Not very verbose. Obviously not Hermes wrote these patents...
No more details, like electrodes, voltages or else - nothing.
Does somebody know the necessary voltage for NaCl to Na and Cl electrolysis? I know the voltage for HCl electrolysis is about 1,9V and NaCl?
Ask Ullmann?
ok, ok........
Nevertheless as I almost finished my new hightekk, highcost, ultramegasuper sophisticated electrolysis experimental setup I will try this soon.
Sounds to good to be true....
Haloform Reaction
Turel - 8-3-2004 at 14:25
Organikum, I am sure you know this is the haloform reaction, using electricity to generate in situ OX- from X- and H2O. The OX- oxidizes the alcohol
to the aldehyde and then the aldehyde undergoes a normal haloform reaction.
The only reason I bring this up is because of previous discussions regarding thermal decomposition of OCl- ions in water. If experimenting with NaCl
electrolysis for making chloroform, consider experimenting with different temperatures. If your results are not satisfactory, try a lowered
temperature, as it may be the problem.
As for the voltage, I don't know it off hand. Sorry.
Organikum - 8-3-2004 at 15:49
I actually didnt know about this electrolytic way to run the haloform reaction - the usual way using insane amounts of bleach was known to me.
And I never liked it.
Thanks for the tip with the temperature - I will give it a try soon as told, sadly the Ullmann doesnt disclose the voltage for NaCl cleavage, but I
guess it will be rather low.
thanks
ORG
The_Davster - 16-11-2005 at 19:08
Dug this up accidently the other day from
"A Laboratory manual of Electrochemistry", Muller, 1931.
Only bromo and iodoforms are mentioned.
Too bad it is always horrendous ammounts of platinum used. But hopefully other
inert electrodes like graphite can be used.
EDIT: DAMN I named the pdf wrong, it should be "bromoform and iodoform by electrolysis"... oops
[Edited on 17-11-2005 by rogue chemist]
Attachment: chloroform and bromoform by electrolysis.pdf (779kB)
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Waffles SS - 27-2-2012 at 22:57
Interesting Method.It wrote we cant use ethanol instead of acetone in bromoform but we can use in iodoform.I want to ask what about chloroform?can we
use ethanol?