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Zyklon-A
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What about electrolysis of concentrated sulfuric acid to make it anhydrous? Has anyone tried this? Pulverulescent wanted to try this
as another rout to oleum in len1's Sulphur Trioxide and Oleum guide.
Quote: Originally posted by Pulverulescent  |
I'm not discarding my ancient idea of trying to electrolyse H2S04 to remove H20 to the point where oleum is produced,
though.
Well, not unless someone's found insurmountable obstacles to that process!
And I have an inert anode!
P |
I'm guessing Pt is required as an anode. Whether or not this will produce oleum, I don't know, but it seems like it could work fine for producing 100%
H2SO4.
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S.C. Wack
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| Quote: Originally posted by blogfast25 | | WE have turned this into something else??? See, I kind of expected that response from you. Read the thread again and stop trying to back
pedal: you lost this argument, plain and simple. |
I haven't been talking through the straw man you and the troll have been building. You're just trying to find a response to the benzene thread. The troll on the other hand has no excuse.
Actually, that's the response I expected from you. Go ahead and post exactly which statement/argument I made that you've proved
wrong.
[Edited on 9-5-2014 by S.C. Wack]
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blogfast25
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What on Earth are you taking about now? The benzene thread??? What does this have to do with anything here?
In which way am I "trying to find a response to the benzene thread"? What you claim is ABSURD, Sir.
Troll? I don't see one. But I do see a twit... and not for the first time either.
[Edited on 9-5-2014 by blogfast25]
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HgDinis25
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Dear S.C. Wack,
| Quote: |
If you're producing fumes like that link does, you're not concentrating the acid...as I've said before the fumes seem to be the result of atmospheric
water, like the hot acid wants it so bad that it'll jump right out of the flask for it... |
you're not concentrating the acid, blogfast proved you wrong in this.
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The azeotrope has nothing to do with fuming in air, and neither do vapor pressure measurements not involving undried open air. There is a clear point
in the 80's percent where fuming from hot open containers exposed to moist air becomes an issue. |
He got it to past 95% so, again, there isn't enough SOx vapors coming out so as to not concentrate the acid.
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You cannot say that more water is being lost if you don't know. I do not say this without having concentrated many gallons of battery acid from
Lowe's. There is a point I stop. |
Now we know that more water is being lost.
You're overreacting to this. You we're wrong, so what? Like Karl Popper stated once, you should be celebrating right now. Thanks to your error we're
now closer to the " truht", we now know something new. No shame in it, we're all wrong from time to time.
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aga
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I was wrong once, i think. Maybe i'm wrong about that.
Hero worship is not such a bad thing.
NurdRage is excellent, amusing, and highly inspirational.
The videos are great !
Science is a different thing though, and blogfast25 has done the experiment, demonstrated the method and the shown results in a way that can be
repeated and checked (measured everything relevant) and is the deserving winner of the Banana of Truth.
S C Wack may not be as highly Gruntled with the result, however the point raised regarding the Loss of SOx in the process is worthy of some
thought, as there is obviously some loss.
Simply piping the vapours through H2O perhaps, or use a Vigreux to better separate the phases ...
I'm a noob, so there's probably obvious reasons why neither would work.
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aga
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benzene thread.
Wierd. i have been looking for that thread since about 20 mins ago.
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blogfast25
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| Quote: Originally posted by aga |
Simply piping the vapours through H2O perhaps, or use a Vigreux to better separate the phases ...
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Go upstairs and look for the file SC linked too: it shows you the kind of apparatus needed to recover the fumes. My German is just 10 - 15 % short of
fully understanding the text though.
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aga
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Danke.
Meine Deutche ist auch noch nicht gut genug, aber ich kann arbeiter.
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macckone
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| Quote: Originally posted by Zyklonb | What about electrolysis of concentrated sulfuric acid to make it anhydrous? Has anyone tried this? Pulverulescent wanted to try this
as another rout to oleum in len1's Sulphur Trioxide and Oleum guide.
| Quote: Originally posted by Pulverulescent |
I'm not discarding my ancient idea of trying to electrolyse H2S04 to remove H20 to the point where oleum is produced,
though.
Well, not unless someone's found insurmountable obstacles to that process!
And I have an inert anode!
P |
I'm guessing Pt is required as an anode. Whether or not this will produce oleum, I don't know, but it seems like it could work fine for producing 100%
H2SO4.
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This is the method to peroxydisulfuric acid.
Not that wiki is the most reliable but:
http://en.wikipedia.org/wiki/Peroxydisulfuric_acid
You can also look for A.J. Hale, The Manufacture of Chemicals
by Electrolysis which has an in depth discussion.
https://archive.org/details/manufactureofche00halerich
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Zyklon-A
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Ok, thanks. The Simad library has that book too:http://library.sciencemadness.org/library/books/the_manufact...
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S.C. Wack
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Did I say that you can't concentrate, say, once you see fumes like in the first picture, or do any of you have any sense? Is If you're
producing fumes like that link does at the end, you're not concentrating the acid, you're just fuming it off
good enough for you?
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blogfast25
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We don't know at which concentration precisely the fuming starts. So how do we know that when it starts water is no longer coming off at a rate higher
than the acid coming off or decomposing? If water is still coming of faster than you lose acid, you're still concentrating, albeit wastefully.
Maybe in a future experiment I'll take samples at various points: start of fuming, 10 minutes in, 20 minutes in, etc, to evaluate concentration.
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aga
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OK.
Enough is enough.
There is only 1 way to settle this - FIIIIGHT !
S C Wack vs Blogfast25
Normal chem fight rules : Method, Experiment, Results, Conclusion.
First one to (verifiable) 98.9% conc. wins.
[Edited on 12-5-2014 by aga]
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blogfast25
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Aga:
You watch too much Harry Hill...
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aga
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This should not have been a surprise, but it actually IS !
Currently i'm boiling down 400ml Brown drain cleaner (says 75% Acido Sulfurico on the label) to which i have added 20% by volume of 3% OTC
H2O2 which has removed the Brown stuff.
At least the solution is Clear now.
Whether the acid will end up Pure is unknown.
Due to Other Things To Do, i have heated/stopped 3 times today.
When i got back to the 'Lab' (such as it is) the liquid levels were 25ml lower than when i switched off the hotplate, and left them to cool (approx 3
hours ago).
A Small Fan is running to help remove the water vapour.
So, i restarted the heating, typed stuff on this website etc, then looked again at the acid (~20 mins)
Liquid levels are back to where i left them, now that the temperature is 180 C ! 25ml just reappeared !
A quick look around to see if there was a grass snake with a wash bottle showed that nothing External had happened.
So, when removing water from Sulphuric Acid by heating/evaporation, the temperature at which Volume is measured is vitally important.
This may not be anything at all to most people here, but it surprised me.
[Edited on 18-5-2014 by aga]
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blogfast25
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aga: just try and boil it down until it starts fuming. My guess is that will give you 95 w% H2SO4 or slightly better.
Nice idea with the peroxide. Might have been better to test on small scale though, to see just how much peroxide you need to oxidise the brown stuff
away...
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aga
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Funnily enough, the 40ml beaker needs cleaning 
[Edited on 19-5-2014 by aga]
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blogfast25
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Please also bear in mind that you should avoid pouring water (or watery solutions) into concentrated sulphuric acid because it can splatter badly. If
you have to (here you had no choice) do it slowly and with constant stirring.
The acid was only 75 % so it wasn't as dangerous but with 98 % this is really not recommended. You should always (where possible) add the acid to
water, not the other way around.
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aga
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Good advice.
I seem to remember that one from way back, so the stirbar was spinning, and the H2O2 went in drop by drop into the cool acid (wasn't cool for long !).
It still wanted to spit and fizzle though, which is where gloves, full-face visor and a fume hood all seemed less than overkill.
Just for kicks i thought i'd see what pH the solution registered on a UI paper strip.
The colour chart doesn't give a reading for Instantly Blackened and totally Dissolved with a pfzzzt sound.
The fume hood fan was upgraded from a PC fan to a 230v extractor at the suggestion of an SM member, and that came in handy today.
[Edited on 19-5-2014 by aga]
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blogfast25
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50 % is enough to destroy ordinary paper.
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aga
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These rubber gloves seem OK with sulphuric acid - not that i've actually tested that theory to destruction.
Presumably there are substances which would destroy rubber gloves instantly.
Are there any Guidelines that should be known, such as neoprene, natural rubber, nitrile etc when dealing with certain chemicals ?
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macckone
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| Quote: Originally posted by aga | These rubber gloves seem OK with sulphuric acid - not that i've actually tested that theory to destruction.
Presumably there are substances which would destroy rubber gloves instantly.
Are there any Guidelines that should be known, such as neoprene, natural rubber, nitrile etc when dealing with certain chemicals ?
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Do a web search on chemical compatibility and your material of
choice. You should turn up lists of chemicals that are compatible
or not recommended.
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Zyklon-A
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Most rubbers hold up just fine with sulfuric acid. It's nitric acid that is scary. You'll need to order gloves online for that.
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macckone
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PVC is compatible with Concentrated Nitric.
Nothing is compatible with fuming nitric but some
things hold up better than others like PVC and
PFA/FEP polymers.
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Zyklon-A
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Yep, you're right. I thought there were some gloves available which are resistant to R/WFNA. But apparently not: http://www.ansellpro.com/download/Ansell_7thEditionChemicalR...
It say PVC holds up poorly to RFNA, and lists nothing that holds up completely. (I assume WFNA and RFNA are nearly the same in this aspect).
I have never worked with concentrated nitric acid (~70%), because fuming nitric acid is almost as easy to make, and has more applications. All I know
is FNA is nasty shit if spilled on skin. 98% sulfuric acid will give bad burns if you don't wash within ~30 seconds. 98% nitric acid will burn within
5 seconds, and will leave yellow stains no matter how fast you wash it off. It catches all OTC gloves on fire within 10 seconds, so wearing no gloves
is probably better than any at all. Anyway, for sulfuric acid, Latex or Nitrile will be fine, for any short period of time.
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