metalresearcher
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Nice experiment: KClO3 + H2SO4 + paper
I performed this experiment 10 years ago and repeated it tonight.
I put some concentrated (< 1ml) sulfuric acid in a test tube and added a knifetip of KClO3. It got brown (HClO3 + Cl2 ?) and added snippets of
paper.
This resulted in sharp reports and recorded it with my Canon.
In the video I added a 1/6 slow motion part which sounds like firecrackers exploding.
https://www.metallab.net/jwplayer/video.php?v=L2NsaXBzL0tDbE...
Note: to repeat this experiment, it can be dangerous as both oxidizers H2SO4 + KClO3 releases toxic and corrosive fumes and organic materials burn
violently as my video shows.
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NEMO-Chemistry
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Very cool
Good video from the camera as well.
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aga
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Wonderful !
Anyone know what is happening there ?
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NEMO-Chemistry
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No but would love to take a guess.
I think the Sulphuric acid just helps rip the paper apart (bond wise) and then its a REDOX with the chlorate.
But equations and decent explanation is not possible currently, but I am working on the learning bit.
I wasnt expecting it to be as fast. It really does perfectly show how careful you have to be with some things
Looks like its more interesting than i thought, take a look here
http://www.sciencemadness.org/talk/viewthread.php?tid=14354
[Edited on 14-10-2017 by NEMO-Chemistry]
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SWIM
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If anybody reading this thread hasn't read the thread NEMO-chemistry posted a link to above, it also says that this experiment should not be scaled up
at all or it will become VERY dangerous.
Sulfuric acid and broken glass shower dangerous.
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NEMO-Chemistry
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Yeah I was way off with the chemistry!! Read the other link for details, that is some seriously dangerous stuff. But credit to the OP, he did a good
job and demo on a safe scale, i also liked the fact the tube was in a heavier walled container as well.
EDIT
Actually I think its worth posting what Woelen said in the other thread on this
"
First a word of warning! Please don't use such large quantities for this experiment. You were lucky that the whole mess did not explode. An explosion
of 4 ml of concentrated sulphuric acid with 1 gram of potassium chlorate can give NASTY burns, sprayed all over your body, not to speak of the glass
shrapnel that will penetrate your body!
The reaction which occurs first is formation of HClO3, which immediately disproportionates into HClO4 and ClO2 (and also some Cl2, O2 and H2O). The
ClO2 gives the red/brown color in the liquid and also is the intense yellow gas above the liquid. It is extremely unstable and easily explodes. The
HClO4 also is very dangerous, because here, it is more or less anhydrous and this is a very reactive and dangerous compound, which ignites and
frequently explodes in contact with organics like paper, sugar, cotton, human skin and human hair.
Please don't do this again with these quantities. If you really want to try again, then take a small spatula of KClO3 and add 2 or 3 drops of
concentrated sulphuric acid to this. With that small quantity you also can study the properties of this mix. An do not forget to have goggles in front
of your eyes!
[Edited on 22-8-10 by woelen]"
[Edited on 15-10-2017 by NEMO-Chemistry]
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metalresearcher
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Quote: Originally posted by NEMO-Chemistry  | Yeah I was way off with the chemistry!! Read the other link for details, that is some seriously dangerous stuff. But credit to the OP, he did a good
job and demo on a safe scale, i also liked the fact the tube was in a heavier walled container as well.
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Indeed for the reason woelen noted, I used only a small quantity and even then I was scared that the test tube would rupture so I put it in an
erlenmeyer flask. But the test tube survived.
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AJKOER
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OK, perhaps first is the formation of the black fine carbon by the action of H2SO4 on paper. It is known that mixing carbon and KClO3 forms a
potentially explosive mixture.
The created HClO3 (from H2SO4 + KClO3) may be further reduced by the carbon, a reducing agent (see discussion at http://pubs.acs.org/doi/pdf/10.1021/cen-v033n003.p211 ) leading to ClO2 (as chlorate + acid + reducing agent forms ClO2, but carbon is not
generally cited as a suitable reducing agent here for its preparation, since it initiates an explosion with ClO2, see https://cameochemicals.noaa.gov/chemical/370 ). Or, the ClO2 may be created per a disproportionation reaction described above.
The carbon may also lead to the formation of CO, which also triggers ClO2 to explode.
In any event, a detonation of the unstable ClO2 may serve to further trigger the C/KClO3/HClO3 explosive mixture.
[Edited on 16-10-2017 by AJKOER]
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metalresearcher
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| Quote: Originally posted by AJKOER | OK, perhaps first is the formation of the black fine carbon by the action of H2SO4 on paper. It is known that mixing carbon and KClO3 forms a
potentially explosive mixture.
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That can be the pops I heard ?
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AJKOER
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I suspect popping sound is likely exploding bubbles of ClO2 in contact with carbon or CO.
Such explosions may be particularly problematic, acting as a possible primer, with larger quantities containing any shock sensitive compositions of
carbon/KClO3/HClO3/HClO4.
[Edited on 16-10-2017 by AJKOER]
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