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AJKOER
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Quote: Originally posted by blogfast25  | AJKOER:
Now seriously, go and BUY some concentrated H2SO4 drain unblocker, some base chemicals and do some basic stuff. Well reported even the simplest of
things are a joy to read. Not so your pseudo-chemical houses of cards in the sky…
[Edited on 25-1-2012 by blogfast25] |
blogfast25: you are right, many of us can still go and buy H2SO4, for now. I have noticed, but I could be wrong, that my bathroom bowl cleaner has
gone form 5% HCl to none. Perhaps part of the green revolution or not.
I viewed this thread more of a puzzle to be solved (I like puzzles). That is, given FeSO4 and some standard available chemicals, make some dilute
H2SO4 (the more concentrated and purer the better).
May the best garage chemist win!
[Edited on 25-1-2012 by AJKOER]
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Neil
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I think Garage Chemist wins that award (and then some) with his manufacture of Oleum.
Start playing with HClOx in real life and not on paper and see if they are still your favourite 
| Quote: Originally posted by blogfast25 | Well reported even the simplest of things are a joy to read.
[snip]
Thanks to you I may never be able to look at a bottle of bleach in the same way… 
[Edited on 25-1-2012 by blogfast25] |
Amen.
and
Amen.
[Edited on 25-1-2012 by Neil]
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White Yeti
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Puzzle solved:
http://www.sciencemadness.org/talk/viewthread.php?tid=2824
"Ja, Kalzium, das ist alles!" -Otto Loewi
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weiming1998
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Or not really.
That requires nitrate salts, remember, and people like me can't find them. Read this http://www.sciencemadness.org/talk/viewthread.php?tid=18588
But I got to admit, why use such an inefficient process as to use bleach on FeSO4? The NaOH in bleach should inhibit chlorine production. Why not use
NaHSO4 solution and Ca(ClO)2 to generate chlorine gas? Why waste the time using a giant pressurized vessel (which most people don't have) and advanced
catalysts, just to make a few tens of mls of SO2Cl2? If you had the condition to concentrate galleons of SO2 and Cl2, I'm sure you can find H2SO4. In
fact, if you had that, I'm pretty sure you can find every chemical that is not a drug precursor.
Now, an idea to drive off HCl/Cl2 in a SO2/Cl2 aqueous solution without driving the SO2 off/decomposing the H2SO4?
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Neil
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http://www.sciencemadness.org/talk/viewthread.php?tid=2824&a...
The Lead chamber thread covers ideas for nitrate free runs and has ideas on sulfuric from Iron sulfates, as linked to above.
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AJKOER
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Actually the Lead Chamber thread on pages 8 & 9 says some very good things about the H2O + H2SO3 + Cl2 ==> H2SO4 + 2HCl route (on the middle of
page 8 starting with un0me2), which is only proceduraly different from adding water to SO2Cl2. That is, (H2O + SO2) + Cl2 vs. H2O + (SO2 + Cl2). If
adding Cl2 to H2SO3 is better, so be it. For the record, I did mention both of these routes, with SO2Cl2 mentioned last, but for those with short term
memory, here is an extract:
| Quote: Originally posted by AJKOER | With reference to Neil point on making things that real labs could order and to refocus on the thread, employing FeSO4, may I suggest the following
path to pure H2SO4:
1. React FeSO4 with Bleach (NaClO) to produce Cl2 (conform with local laws).
2. Create Chlorine water (use freshly boiled distilled H2O to remove CO2).
3. Add SO2 to the Chlorine water. Reaction:
H2SO3 + Cl2 + H2O --> H2SO4 + HCl
or prepare SO2Cl2, .....
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Here is a convenient link to the Lead Chamber thread:
http://www.sciencemadness.org/talk/viewthread.php?tid=2824&a...
In particular on page 9 of Lead Chamber thread, and off topic for that thread, but on key for this one:
| Quote: Originally posted by Formatik | References in Gmelin verify the reaction goes as thought: when SO2 and Cl2 are led into water, this exotherms a bit and accumulates the H2SO4 as the
HCl concentration decreases. Neumann described the reaction is going rapidly and almost completely (95-100% theoretical amounts were converted), the
sulfuric and hydrochloric acids result immediately as fine droplets/fog, these are difficult to absorb and also pass over, as gases and water
initially interact.
The patent mentioned of Stolle, leads same parts SO2 and Cl2 into water, eventually raising the temperature to 250 deg., yielding 90% H2SO4 and conc.,
free from Cl2 and SO2, aqueous HCl. Neumann's process is much more descriptive.
Neumann also described despite having used a Cl2-excess, a significant amount of SO2 got solubilized in H2SO4, since SO2 solubility increases with
H2SO4 concentration. Though experiments also showed conc. H2SO4 which had Cl2 or SO2 solubilized in it, after blowing in air for 15 minutes, were
almost completely removed.
It seems this thread is the designated stickied sulfuric acid thread. I would retitle it as the sulfuric acid preparation thread, or remove the
non-Chamber discussions and sticky those with said title instead. Good eye on that reference, I also found it through Gmelin.
| Quote: Originally posted by 497 | | Do you think bubbling Cl2 + SO2 into water could get H2SO4 concentrated past azeotropic? I don't remember if there are any side reactions that could
occur in a mixture of HCl, conc. H2SO4, Cl2, SO2 and H2O... I can't think of any off the top of my head, besides formation of sulfuryl chloride, but
that should not occur without a catalyst right? |
I doubt it's of concern. Neumann described that after the reaction heat slows down, that the gases come out ununited. This heat is especially large
when water is first consumed in the reaction. Their later experiments used additional heat (60-92 deg), to make the reaction go much faster.
Concerning the concentration of H2SO4 obtained by combination of SO2 and Cl2 with H2O, Neumann says it is that of the Chamber acid or Glover acid
(66-88%). That's the raw figure then, it can be concentrated further by regular means. For practical purposes, instead of H2O, conc. HCl was
recommended. Then when a specific gravity of 1.6 is reached, the hydrochloric acid content has been nearly completely removed.
[Edited on 20-8-2010 by Formatik][/rquote
[Edited on 26-1-2012 by AJKOER] |
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AJKOER
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One manner a garage chemist could implement the
H2O + H2SO3 + Cl2 ==> H2SO4 + 2 HCl
reaction with limited equipment in a safe manner is as follows:
1. Prepare Chlorine hydrate, Cl2 +7.3 H2O (note, for calculation purposes, the actual value is not 7.3, but 7.27 plus or minus .17). The recommended
process is bubbling Cl2 into a cold (below 0 C) solution of CaCl2. My variation is to prepare HOCl (weak acid like H2CO3 to Ca(OCl)2/CaCl2 solution
and filter). Then add an appropriately small amount of H2O2. Reactions:
Ca(OCl)2 + H2CO3 --> CaCO3 (s) + 2 HOCl
2 HOCl + H2O2 ---> HOCl + HCl + H2O + O2
HOCl + HCl <---> Cl2 + H2O
Now, freeze the Chlorine water and salt solution, and harvest the long green crystals (I done this). Let dry in the cold (stable at under 9 C in an
open vessel). In a closed vessel, also stable at/near room temperature.
2. Fill a glass vessel with some SO2 (liquid or gas or use H2SO3) and add the Chlorine hydrate and seal. Place in sunlight and observe the reaction
from a distance (ice bath may be necessary to control temperature).
3. Upon completion, add/remove H2O to obtain desired H2SO4 strength. Heat/bubble air into the solution to remove unwanted HCl.
[Edited on 26-1-2012 by AJKOER]
[Edited on 27-1-2012 by AJKOER]
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White Yeti
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reactions not balanced are
"Ja, Kalzium, das ist alles!" -Otto Loewi
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AJKOER
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Thanks, I was in a hurry as I actual changed from NaClO to Ca(OCl)2 (equations now edited).
As a self criticism, I wonder if the Chlorine hydrate would be completely free of CaCl2 (as not, it would increase HCl and reduce the H2SO4 yield).
One could dilute the solution, however, before cooling and retrieving the Cl2+7.3H2O, and thereby reduce the potential contamination. Given the
reaction:
Cl2 + H2O <----> H(+) + Cl(-) + HOCl
as the solution starts off alkaline, dilution would lower the pH and move the reaction to the left (more Chlorine water).
Or, one could also re-dissolve the Chlorine hydrate in distilled water and attempt re-crystallization.
[Edited on 26-1-2012 by AJKOER]
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White Yeti
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if any at all
"Ja, Kalzium, das ist alles!" -Otto Loewi
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blogfast25
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| Quote: Originally posted by AJKOER | 3. Upon completion, add/remove H2O to obtain desired H2SO4 strength. Bubble air into the solution to remove unwanted HCl.
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Really? You're gonna separate H2SO4/HCl by 'bubbling air through it'? You're quite the Chief Engineer! 
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AJKOER
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blogfast25:
Please re-read my extract from the Lead Chamber thread above. Per Formatik:
"The patent mentioned of Stolle, leads same parts SO2 and Cl2 into water, eventually raising the temperature to 250 deg., yielding 90% H2SO4 and
conc., free from Cl2 and SO2, aqueous HCl. Neumann's process is much more descriptive.
Neumann also described despite having used a Cl2-excess, a significant amount of SO2 got solubilized in H2SO4, since SO2 solubility increases with
H2SO4 concentration. Though experiments also showed conc. H2SO4 which had Cl2 or SO2 solubilized in it, after blowing in air for 15 minutes, were
almost completely removed."
So the combination of heat (unclear to me as to whether the source is only the reaction or external also) and air removes Cl2, SO2 and aqueous HCl
yielding 90% H2SO4.
However, you may have a point and I have edited the process to include treating with heat and air.
[Edited on 27-1-2012 by AJKOER]
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weiming1998
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Bubbling air/ozone through water is not going to remove HCl. What about silver sulfate in the solution? It is slightly soluble in water and will
actually increase H2SO4 yields. But where do you get something like silver sulfate?
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entropy51
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As best I can discern, no one who posted in
that thread actually made any H2SO4. I find it amusing, but not surprising, that you cite such balderdash as a reference.
No one who actually works with chemicals could actually believe that there is any practical utility in these Rube Goldberg schemes.
If you perform a six step synthesis, and the yield of each step is 50%, then the overall yield is 1.5%.
If you're so sure of yourself, why not perform the experiment and post the data? Otherwise this is all just brain farts.
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AJKOER
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As the H2SO4 becomes more concentrated, being a powerful dehydrating agent, we may have essentially hydrogen chloride in H2SO4. The combination of
heat and aeration may be able to dislodge it from the H2SO4.
I do agree with weak H2SO4, no such luck.
-----------------------------------------------------------------------------
To prepare Ag2SO4, assuming no access to H2SO4, I would try Silver acetate (AgC2H3O2) in Acetic acid (where it is soluble) and add Epsom's Salt
(MgSO4).
Possible reaction:
2 AgC2H3O2 + MgSO4 --> Ag2SO4 (s) + Mg(C2H3O2)2
where I suspect/hope that Silver sulfate does not dissolve in weak Acetic acid. Fortunately, per one source, it does dissolve in dilute H2SO4, making
it possibly effective for our purpose.
Ag2SO4 + HCl --> 2 AgCl (s) + H2SO4
Assuming AgCl is not soluble in H2SO4.
[Edited on 27-1-2012 by AJKOER]
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AJKOER
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Entropy51:
I agree with you.
Until someone on Sciencemadness can successfully perform a synthesis, even on a micro level, lets honestly state it is just theoretically possible.
[Edited on 27-1-2012 by AJKOER]
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White Yeti
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Is it time yet for a moderator to lock this thread? The OP is deaf to any criticism, most of which is justified. We are just wasting breath and
heading nowhere but deeper into the abyss of untruth and armchair speculation; an abyss to which there is no bottom
"Ja, Kalzium, das ist alles!" -Otto Loewi
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weiming1998
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Yes, I have nothing to say, because everything is speculation in this thread.
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Bot0nist
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| Quote: Originally posted by White Yeti | | Is it time yet for a moderator to lock this thread? The OP is deaf to any criticism, most of which is justified. We are just wasting breath and
heading nowhere but deeper into the abyss of untruth and armchair speculation; an abyss to which there is no bottom |
Crying out for a moderator in a thread does not signal them. If you have enough disdain for a thread to make multiple posts in it, just to call for
it's closure, why not simply report the thread to the moderators. Unlike what your doing here, this will both call the moderators attention to the
thread you have a problem with, and stop you from inflating your post count with useless posts. (since they don't aid in closing a problem thread,
and they only increase it's size and bumps it up)
[Edited on 27-1-2012 by Bot0nist]
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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AJKOER
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SUMMARY OF THREAD MAKING DILUTE (OR BETTER) H2SO4 FROM FeSO4
1. Using just FeSO4, and heating yields SO2 and SO3, an agreed upon path to H2SO4.
2. Direct oxidation of aqueous FeSO4 with air via microbes is a slow process (measured in months), but tried and true having been replaced by modern
methods.
3. The oxidation of H2SO3 with Cl2 is less favored by some and proclaimed by others. Following the precise procedure as laid out in a patent is
recommended. Good off topic discussion in the Lead Chamber thread.
4. The direct reaction of SO2 and Cl2 in the presence of a catalyst had even less appreciation over questions of volume of H2SO4 that could possibly
be created. Use of cooled SO2 and/or Chlorine hydrate, as possible solutions, drew no support.
Please comment if you have a significantly different opinion on any of these points.
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497
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Very high yields of SO3 are said to be obtained by pyrolysis of basic iron sulfates at easily manageable temperatures. Why worry about chlorine
compounds?
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weiming1998
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Easily manageable? That's 700-800 degrees, according to posts here! (Though Wikipedia lists the decomp temperature of FeSO4 at 480 degrees, which
might be achievable by a stove) Also, if you want to make H2SO4 with SO3, you must first have H2SO4. you also need a complete glass distillation set,
as SO3 will attack pretty much everything else. It is also dangerous to handle, will crisp your skin instantly when spilt, and reacts violently with
water (I have never seen the reaction of SO3 and water though).
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AJKOER
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An important point per Weiming that applies for all of these synthesis.
H2SO4 and nearly all preparatory routes are inherently dangerous. Should never be attempted by the inexperienced and certainly without ample safety
precautions.
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weiming1998
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Even conc.H2SO4 or NaOH is nothing compared to SO3, in terms of corrosiveness. Acids attack skin by denaturing protein and absorbing all the water in
cells, which is what makes H2SO4 much more corrosive than HCl, because it's hygroscopic! SO3 is almost as attracted to water as P2O5 and will suck
every molecule of water out of a compound. It will do the same to your skin. Also, I hear people comparing the violent reaction of it in water with
cesium in water, though I suspect it to be exaggeration. It does form a fog of concentrated H2SO4 when in contact with water though, which, if you
breathe it in, damage your lungs irreversibly.
Overall, some route of making H2SO4 can be "quite safe" ( to responsible and careful people) But SO3 is not one of them, unless you have complex
equipment. I tried to make SO3 with NaHSO4 before on a stove. It didn't work. I'm glad it didn't, and I will never work with SO3 unless I have all the
protective equipment I need.
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497
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Try like 500-600* and the option of doing it in the microwave may simplify things a lot further. Also, just because one creates SO3 does not mean they
must literally handle it. There is no reason you couldn't devise a simple system to absorb it as it is produced, while you are nowhere near it.
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