RogueRose
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KCl solution sparking in microwave but nopt with NaCl
Was doing a simple evaporation of about 30ml of saturated KCl (room temp) and 30ml NaCl (room temp) - both in separate beakers. The KCl created
little sparks very near the surface (IDK if it was on the wall of the beaker @ the meniscus or in the solution). These didn't look dangerous, but
they were very noticeable and about 1-5mm in diameter.
What was odd was that this happened within 5 seconds of turning on the microwave (1000w - on high) while the NaCl did nothing after 30 seconds except
precipitate some crystals.
The odd thing is that I evap't a beaker of about 600ml of KCl (heated to boiling for about 10 mins) and I didn't see anything happen then. I stopped
before the amount of liquid dropped below 400ml though.
What is happening here. Is it the H2 seperating and igniting or is it K and Cl separating and the K igniting with water?
Very odd from my experience.
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ficolas
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Are you sure the KCl didnt have any contamination?
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Sulaiman
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What color were the 'sparks' ?
CAUTION : Hobby Chemist, not Professional or even Amateur
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phlogiston
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Share this observation with an 'hydrino' believer. He'll go crazy.
[Edited on 6-6-2017 by phlogiston]
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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tshirtdr1
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Sodium hydroxide solution will spark in the microwave as well. Found that out the hard way.
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RogueRose
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Sorry for the delayed response. The color was a orange/yellow or yellow/orange. they were small so IDK which was the stronger color. I would guess
orange. It did seem like there was some kind of "static" (electrical) spark that may have initiated the explosion/spark - meaning it looked like a
white spark that grew into a orange yellow tiny flame under water.
I'll see if I can replicate it again with another soluition.
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AJKOER
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Here is a prior comment I once made when experimenting with N2O and NaOH in a microwave:
Quote: Originally posted by AJKOER  | I read an MSDS on N2O that noted a hazardous reaction between NaOH (and KOH) and N2O (see https://www.google.com/url?sa=t&source=web&rct=j&... ). Now , a MSDS is generally not good source on points of chemistry, but upon
attempting this reaction twice, it is unlikely I will repeat. The reaction is best described even with small amounts as dangerously exothermic. My
speculation on how this warning became worthy of recognition was most likely a warehouse fire with evident fireworks observed.
I first place some 3% H2O2 (infused with N2O) and N2O gas itself, in a container in the microwave and heated to release any dissolved N2O. I then
carefully drained off the fluid leaving a moist container with N2O and some O2 and inserted dry NaOH. On my first attempt employing all glassware
while heating the mixture in a microwave, the porcelain disk containing the NaOH in an atmosphere of N2O and water vapor did not crack, it shattered
at the first sign of a yellow spark. The second attempt in a microwave oven produced significant yellow fireworks with now a plastic container
subsequently catching on fire. The white salt created seemed resistance to dissolving in NaOCl.
Speculation on possible reaction paths: As noted in the opening thread above, to quote:
"A side comment I found interesting is how N2O in N2/O2 mixture is converted into NO in a microwave..."
So one might expect:
2 NaOH + NO + NO2 → 2 NaNO2 + H2O (reference http://www.allreactions.com/index.php/group-1a/natrium/sodiu... but for cold NaOH )
but not readily as the rate controlling step is dependent on the formation of the reactive nitrogen species via the microwave radiation to produce the
required NO:
N(2D,2P) + O2 → NO + O (reference, p. 144 at http://books.google.com/books?id=8MXX01Qw_G0C&pg=PA143&a... )
Other possible paths, both exothermic, include (source: see http://connection.ebscohost.com/c/articles/7644257/gas-phase... or http://scitation.aip.org/content/aip/journal/jcp/85/10/10.10... ):
NaO + N2O = Na + N2 + O2
NaO + N2O = NaO2 + N2
where any formed Sodium metal would rapidly and violently react with water vapor. I also found this article presented at the 14th International
Conference on the Properties of Water and Steam in Kyoto titled "The role of water in N2O anion dissociation and reaction rates of N2O with hydrated
electrons in high temperature water" by Kenji Takahashi et al. available at https://www.google.com/url?sa=t&source=web&rct=j&... also informative.
With respect to Sodium peroxide, per Wikipedia (see http://en.m.wikipedia.org/wiki/Na2O2 ) and http://www.allreactions.com/index.php/group-1a/natrium/sodiu... :
2 Na2O + O2 → 2 Na2O2 (or 4 NaO between 250—350° С, under pressure)
and would assume (not certain) the Na2O or the NaO could be derived under these particular reaction conditions from the NaOH (perhaps 2NaOH + N2O →
2NaO + H2O + N2 in hot water vapor, or via the direct action of H2O2, formed by active oxygen on decomposition of N2O, with NaOH) to be able to accept
the above reaction path (which appears to only require strong heating of NaOH in the presence N2O and possibly O2, and does account for the
'fireworks' effect).
[Edited on 13-8-2014 by AJKOER] |
The referenced thread lies, fittingly, in the Energetic Materials forum.
Warning, repeating the above or your experiment may be detrimental to glassware and a possible fire hazard. Wear safety gear and take appropriate
precautions.
[Edited on 10-6-2017 by AJKOER]
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RogueRose
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Well I replicated the experiment with a known solution this time (wasn't 100% sure last time what it was - only about 98%). I got a sustained yellow
spark of about 8mm for 25 seconds at the water line as the water furiously boiled. It took about 3-4 seconds for it to start then it continued in a
consistent manner (may have grown somewhat to 10-12mm by the end) until I stopped it. I thought it was odd that it was only in one place so I
swirrled the solution, replaced it and tried again and nothing that time, but it immediately boiled (expected..)
8 hours later....
I tested this again with a video camera and have the results which clearly show the spark/arcing. I think I've figured out why I can't replicate this
after running the test 10-12 times where it seems to stop after a point.
I also tested the same amount or water to see how long it took to boil and the KCl solution boiled in just over 1/2 the time as did the plain water
(13 seconds vs 25 seconds for a 30ml or sat solution vs 30ml pure water). I'm wondering if the salt in the solution allows for more energy to be
absorbed than with plain water.
I looked into the hydrinos thing and it seems interesting and I understand the theory of "below ground" charge level and I've had similar thoughts
about that - didn't know it was a theory until now. Does what is happening in this reaction have anything to do this this? That is where I'm not
sure how it relates.
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RogueRose
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AJKOER - I read your post/quote and I see that he probably had similar results I had, maybe a little more violent than mine. I was using thick
(pyrex kitchen measuring cup) glass to hold the water and it seems to hold up fine.
The first time I experienced it I was startled because I wasn't expecting the sound. It sounded the same as leaving Al foil in the microwave with the
addition of some "thumps" or pops, maybe 1-2 a second.
I was wondering if the K and Cl were separating then the K reacting with the water giving the flash - or if water was splitting and causing the H2 to
ignite somehow. When I had the spark going for almost 25 seconds I opened the door and didn't smell anything abnormal (like Cl2) so I don't think the
KCl was splitting.
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phlogiston
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| Quote: Originally posted by RogueRose |
I looked into the hydrinos thing and it seems interesting and I understand the theory of "below ground" charge level and I've had similar thoughts
about that - didn't know it was a theory until now. Does what is happening in this reaction have anything to do this this? That is where I'm not
sure how it relates. |
Well, calling it a theory is giving it too much credit. At least it is not widely accepted, and probably a (very elaborate) scam.
The relation with your experiment is that the hydrino 'theory' says that electrons cannot decay to the lower energy orbitals by emitting radiation, as
happens for decay between normal orbitals, but only by contact with certain catalysts (that can absorb just the right amount of energy) Potassium is
such a catalyst, and sodium is not.
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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RogueRose
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| Quote: Originally posted by phlogiston | | Quote: Originally posted by RogueRose |
I looked into the hydrinos thing and it seems interesting and I understand the theory of "below ground" charge level and I've had similar thoughts
about that - didn't know it was a theory until now. Does what is happening in this reaction have anything to do this this? That is where I'm not
sure how it relates. |
Well, calling it a theory is giving it too much credit. At least it is not widely accepted, and probably a (very elaborate) scam.
The relation with your experiment is that the hydrino 'theory' says that electrons cannot decay to the lower energy orbitals by emitting radiation, as
happens for decay between normal orbitals, but only by contact with certain catalysts (that can absorb just the right amount of energy) Potassium is
such a catalyst, and sodium is not. |
So does this help their claim/theory or contradict it? I assume that the reaction may be perceived as giving off more energy - with the
ark/spark/flash. Is that what you are speaking about?
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