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Keras
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Quote: Originally posted by hodges  |
From the videos I've watched, this reaction appears to work the best with acetone, with ethanol being a poor second. If you used isopropanol, I'm
guessing you got acetone first of all, then that was probably oxidized second as well, which would explain why it worked better.
Not sure what reaction might occur with benzyl alcohol, but one thing to note (as you probably have already) is that benzyl alcohol boils at over
200C. So you will definitely need to heat it to get an appreciable amount of vapor for the reaction.
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I’m not sure what acetone would be oxidised into. To me, isopropanol gives acetone, but acetone should be pretty unreactive. The reaction works
pretty well with isopropanol, even better than with alcohol (but that can be just due to random circumstances).
As for benzyl alcohol, I tried once, but it didn't work. I suspect I didn't heated the beaker enough, so I’ll have to try again at a higher
temperature.
It is surprising though that, in every case, when the red-hot copper coil is plunged into the vapour, it doesn’t burst aflame. That baffles me.
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hodges
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According to this site: How to Make Copper Glow Red Hot With Acetone
Copper catalyzes the oxidation of Acetone to acetaldehyde, carbon dioxide, and water.
CH3COCH3 (g) + 3/2O2(g) --> CH3CHO(g) + CO2(g) + H2O(g)
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DraconicAcid
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| Quote: Originally posted by Keras | | It is surprising though that, in every case, when the red-hot copper coil is plunged into the vapour, it doesn’t burst aflame. That baffles me.
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Oddly enough, that's happened to me every time I've tried that reaction.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Keras
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It did ignite two or three times, but that’s a very minor occurence (I must have tried it twenty or more times). Probably the reaction works best
when there is not enough oxygen to sustain a full combustion?
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Keras
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Interesting. I also note that the web site quotes the formation of ketene, which would probably arise from acetone pyrosis on the red-hot copper (as
well as methane). I suppose, however, that this is an endothermic, non self-sustaining reaction.
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zed
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The reduction of Benzoic Acid to Benzaldehyde is not especially difficult. But, it isn't exactly easy, in this era of chemical restrictions and
overall high prices.
As I recall, the Rosemund reduction works pretty well. I'll find an example.
http://orgsyn.org/demo.aspx?prep=cv6p1007
[Edited on 22-3-2022 by zed]
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Fantasma4500
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i tried benzoic acid with galinstan and aluminium- didnt work
it did reduce KNO3 into KNO2 in solution though, only very small scale experiment. its somewhat possible with ascorbic acid
seems you might have to turn benzoic acid into benzene and then go from there, sadly. not that big problem since theres toluene in gasoline.
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njl
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You mentioned earlier that you had some success with ascorbic acid, which I find hard to believe. How did you verify that?
Reflux condenser?? I barely know her!
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Fantasma4500
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| Quote: Originally posted by njl | | You mentioned earlier that you had some success with ascorbic acid, which I find hard to believe. How did you verify that? |
simply by odor, i dont think i had generated enough to precipitate it out with NaHSO3. youre welcome to try it out for yourself
using galinstan i only used water, no base or acid was added- benzoic acid would react with base to form sodium benzoate which should be more
resistant to reduction and im a bit worried the gallium would react with acid, though that would increase the reaction speed and hydrogen formation
speed
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Fantasma4500
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i just came across one of chemplayers videos, it was about the video where he mixed up calcium salts and thermally decomposed them to form other
compounds- benzaldehyde was attempted but he didnt use vacuum or inert atmosphere so it didnt work, but there was a hint of benzaldehyde so with
vacuum it should be well doable
https://www.bitchute.com/video/DgHHnEGQVaCp/
calcium benzoate + calcium formate was the mix used, i believe someone hinted at it in this thread, maybe one could add some ethanol to push out
oxygen from the apparatus, maybe simply add in some butane instead and then clamp the whole rig up so that it can just barely expel excess gas?
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