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weiming1998
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Would a complete distillation equipment fit inside a microwave? Maybe if you have a tiny distillation setup that makes about 1ml of SO3. Also, if
microwaves can achieve temperatures like that, then food coming from it would be turned to charcoal. The simple system thing works, if you already has
concentrated H2SO4. SO3's direct reaction with water might be sufficient enough to crack the glass container.
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497
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Okay you obviously don't have near the level of understanding required to do such a thing without being spoonfed every detail.
For anyone else out there interested:
It is easy to pass a small tube through the side of a microwave oven, it is easy to achieve temperatures up to 1000* using iron oxides, and/or
graphite susceptors in a home microwave.
If you can't figure out how to get a small amount of concentrated sulfuric to absorb the SO3, there is no hope, come back in a couple years when you
have finished puberty.
Edit
Since the hematite produced by decomposition of Fe sulfates absorbs microwaves, there may not even be a need to use any additional susceptor. Possibly
just a few seed particles would be needed at the beginning. This means you could avoid all the bulk heat transfer constraints usually present. It also
means a simple borosilicate flask could be used. A layer of microwave nonabsorbent insulation may be easily sintered on the inside of the flask to
shield the flask from direct contact with hot oxide particles. A paste made with fine silica should do the trick. Such an internally insulated,
internally heated flask could be valuable for a number of high temp reactions that are normally done in quartz tubes and such.
[Edited on 28-1-2012 by 497]
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weiming1998
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Obviously you don't have the brains to make SO3 either without hurting yourself if you have to resort to direct insults.
Graphite might work to transfer the heat to the NaHSO4/FeSO4, but even then I doubt it would get hot enough for it to decompose. Making a miniature
model of a complex distillation kit in a microwaveand sticking holes in it is not what I, or most people want for a few mls of concentrated H2SO4. If
you need SO3 for experiments that must require it, fine, but just for H2SO4, there are much better ways that don't require SO3, high temperatures,
poking holes in microwaves, miniature distillation kits, and idiots using ad hominem.
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497
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Actually, travelling in foreign countries for the last few months makes any experimentation impossible.
Do you have any evidence at all to back up a single one of the assertions you've made in the last couple posts?? Negative speculation like that is
entirely useless. If you find any evidence that pertains to my posts, I would be interested to see it.
Why do you keep talking about complex mini distillation kits? Last I checked, a 250ml rbf would fit in a microwave. The whole point of what I said
earlier was that there would be no need for a condenser at all! On top of the rbf you could put a right angle inlet adapter such as the ones here: http://unitedglasstech.com/Adapters.htm
Then a couple feet of teflon tube could lead from the adapter, outside the microwave directly in to a flask of H2SO4. Drilling a hole in a microwave
is as easy as drilling a hole in any other sheet metal. It is not dangerous if the hole is fairly small, and you should be far away while it is
running anyway.
You could be making more like liters a day of SO3, not a few ml. Just because you happen to not care about oleum/SO3 does not mean anything. Based on
the posts and number of views that the SO3 synthesis threads in prepuplication recieved, I'd say plenty of people would be interested.
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blogfast25
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That’s a slanderous lie! I’ve personally checked all steps and they should all give yields between 114.5 and 121.1 %, resulting in an overall
yield of about nearly a 1000 %!
{irony off}
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weiming1998
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Quote: Originally posted by 497  | Actually, travelling in foreign countries for the last few months makes any experimentation impossible.
Do you have any evidence at all to back up a single one of the assertions you've made in the last couple posts?? Negative speculation like that is
entirely useless. If you find any evidence that pertains to my posts, I would be interested to see it.
Why do you keep talking about complex mini distillation kits? Last I checked, a 250ml rbf would fit in a microwave. The whole point of what I said
earlier was that there would be no need for a condenser at all! On top of the rbf you could put a right angle inlet adapter such as the ones here: http://unitedglasstech.com/Adapters.htm
Then a couple feet of teflon tube could lead from the adapter, outside the microwave directly in to a flask of H2SO4. Drilling a hole in a microwave
is as easy as drilling a hole in any other sheet metal. It is not dangerous if the hole is fairly small, and you should be far away while it is
running anyway.
You could be making more like liters a day of SO3, not a few ml. Just because you happen to not care about oleum/SO3 does not mean anything. Based on
the posts and number of views that the SO3 synthesis threads in prepuplication recieved, I'd say plenty of people would be interested.
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That might work, sorry for insulting you.
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497
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Thanks. Also it is worth mentioning that SO3 will dissolve in many organic solvents forming more or less stable complexes. DMF, pyridine, alkyl
acetamides, dioxane, and DMSO are examples.
I'm really dying to try this out... but it is impossible for at least another couple months or more.  So if anyone out there has an expendable microwave and some FeSO4 I emplore them to try it out. Pretty much grind some
FeSO4 with graphite, throw it in some sort of dish or flask, wrap some fiberglass around it and microwave it. Obviously outside, because if it works
as I hope there will be quite a bit of thick white sulfuric mist produced. Dissolving the residue in water and weighing the insoluble fraction will
tell you the yield.
[Edited on 30-1-2012 by 497]
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AJKOER
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Just asking, but wouldn't SO3 do a job on the microwave itself (or its circuitry)?
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Neil
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Oh yes. It would do a pretty good job on it.
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497
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Uhh, the SO3 will most definitely not make it far out of the crucible. Fortunately, I believe many microwaves have fans that suck air through the
magnetron and then blow into the cavity (while turning the thin metal wave chopper in the process). So the positive pressure in the cavity should
mostly protect the circuits. Also, as the resulting sulfuric mist is notoriously reluctant to condense on to anything, corrosion should be minimal.
Even still, don't use your mothers $300 microwave for that experiment. Cheap/free functional microwaves are plentiful most places, and they are useful
for so many other things.
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Neil
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And the potential for the vapour to ionize and give you a plasma sun made out of S and O?
Why would the vapours not want to leave the crucible?
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497
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... because they would instantly react with humidity to form highly uncondensable sulfuric mist. I didn't mean they wouldn't leave, just that SO3 is
unlikely to survive in the atmosphere long enough to go far. Especially since the open crucible experiment would just be a small scale test of
concept. Or you could pipe it out of the microwave and not have to worry.
[Edited on 30-1-2012 by 497]
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Neil
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ahh you were being very literal, I conceded that yes you are likely right 
But then you still have the problem of all that sulfuric acid/oxide fume blowing around and the chance of turning the microwave into a sulfur lamp.
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497
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I guess that's why some would call it an experiment...
If you're that worried about the microwave, doing any chemistry in it is unadvisable.
Sulfur lamps operate under pressure, without oxygen present. But, yes some sort of plasma is still possible I suppose? Can anyone confirm? That would
be pretty cool in itself.
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watson.fawkes
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I can't confirm from direct
experience, but thermal runaways are ordinary in microwave ovens with certain materials. The issue is that absorption changes by orders of magnitude
when you get more free electrons. So the first drop of liquid can superheat, and if that evaporates and ionizes, the first bit of plasma absorbs even
more heat. I don't know the absorption coefficients, but I have to imagine they've already been measured.
If you want to try for a plasma, you want as rapid heating as possible. Loosing heat by conduction minimizes the runaway effect. You want to dump many
watts into the smallest volume. Two pieces of advice. First, promote standing waves in your oven. Easiest way to do this is to remove the stirrer. If
you're really diligent, tune the cavity size to be integral multiples of the half-wavelength. Second, keep your sample at about the quarter-wavelength
diameter, and locate it over one of the standing wave antinodes. You'll get a single point of high-concentration RF energy.
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AJKOER
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Before this thread is closed, it should be mentioned (albeit somewhat obvious), there is a potential path to dilute H2SO4 via direct hydrolysis of
FeSO4 "under air". Source:
"Hydrolysis of Iron Ion in Chrysotile Nanotubules: A Template Effect on Crystal Growth"
by Sumio Ozeki, Hiroyuki Uchiyama, Motomi Katada
Langmuir, 1994, 10 (3), pp 923–928
DOI: 10.1021/la00015a051
Publication Date: March 1994
To quote: "When aqueous solutions of FeSO4 are hydrolysed under air at room temperature, various products,.." and other than FeOOH, Fe3O4, Fe2O3
listed, there could be some dilute H2SO4 along with aqueous FeSO4, I suspect.
Whether the amount of dilute H2SO4 created is significant may be debatable.
Note, this is a laboratory induced hydrolysis without the helping hands (figuratively speaking) of little microbes, previously discussed.
Link:
http://pubs.acs.org/doi/pdf/10.1021/la00015a051
Here is a full paper discussing Chrysotile-Nanotubes:
http://www.lebsc.it/wp-content/uploads/2011/02/2_Geoinspired...
[Edited on 2-2-2012 by AJKOER]
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weiming1998
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| Quote: Originally posted by AJKOER | Before this thread is closed, it should be mentioned (albeit somewhat obvious), there is a potential path to dilute H2SO4 via direct hydrolysis of
FeSO4 "under air". Source:
"Hydrolysis of Iron Ion in Chrysotile Nanotubules: A Template Effect on Crystal Growth"
by Sumio Ozeki, Hiroyuki Uchiyama, Motomi Katada
Langmuir, 1994, 10 (3), pp 923–928
DOI: 10.1021/la00015a051
Publication Date: March 1994
To quote: "When aqueous solutions of FeSO4 are hydrolysed under air at room temperature, various products,.." and other than FeOOH, Fe3O4, Fe2O3
listed, there could be some dilute H2SO4 along with aqueous FeSO4, I suspect.
Whether the amount of dilute H2SO4 created is significant may be debatable.
Note, this is a laboratory induced hydrolysis without the helping hands (figuratively speaking) of little microbes, previously discussed.
Link:
http://pubs.acs.org/doi/pdf/10.1021/la00015a051
Here is a full paper discussing Chrysotile-Nanotubes:
http://www.lebsc.it/wp-content/uploads/2011/02/2_Geoinspired...
[Edited on 2-2-2012 by AJKOER] |
FeOOH? Does that even exist? Also, FeSO4 definitely hydrolyzes to Fe(OH)3 or Fe2O3/H2SO4. But NaCl also hydrolyzes into minute amounts of HCl and
NaOH, namely, 10^-7 moles of HCl/NaOH/L. FeSO4 solution is certainly going to have more sulfuric acid because Fe(OH)3 is both insoluble and an
extremely weak base. That leads to a question, what is the pH of FeSO4?
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Poppy
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I think ferrous sulfate pH must be quite acidic too but far from FeIII. Just oxydising the ferrous sulfate with H2O2 and filtering the iron hydroxide
mesh will be oK. Then diluting again with water to lower the pH even more releasing more H2SO4 which can be boiled and re-concentrated after repeating
this step about 3 times will result a very pure dilute sulfuric acid dilute solution whichcan be concentrated without thinking much about stoichometry
and pH measurements will work fine.
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AJKOER
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To answer Weiming1998, "FeOOH? Does that even exist?"
Per Wikipedia, http://en.wikipedia.org/wiki/Iron_oxide
Oxide/hydroxidesMain article: iron(III) oxide-hydroxide
goethite (α-FeOOH),
akaganéite (β-FeOOH),
lepidocrocite (γ-FeOOH),
feroxyhyte (δ-FeOOH),
ferrihydrite (Fe5HO8·4H2O approx.), or 5Fe2O3•9H2O, better recast as FeOOH•0.4H2O
high-pressure FeOOH"
Another source writes goethite as α-FeO(OH), a form of Iron(III) oxide hydroxide, which is commonly found in nature. It is formed when freshly
precipitated Iron(III) oxide hydrate is heated in 2 M NaOH with superheated steam.
Lepidocrocite γ-FeO(OH) is an unstable variation of FeO(OH).
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weiming1998
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The hydrolysis of Fe2(SO4)3 is going to be a better idea because it is more acidic, plus Fe2O3/Fe(OH)3 is a much weaker base/less soluble than
Fe(OH)2.
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