Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2    4
Author: Subject: cleaning sulfuric acid
MadHatter
International Hazard
*****




Posts: 1035
Registered: 9-7-2004
Location: Mid-Atlantic
Member Is Offline

Mood: Patience growing thin !

[*] posted on 14-6-2005 at 20:14
Roebic


Bromic Acid, is that the Roebic Drain Flow brand of sulphuric acid you're describing ? Apparently,
the carbon is thrown in as some kind of warning indicator to a novice. Personally, I never
worried about that shit. Made good vacuum distilled nitric acid in any event. The carbon
was more of a pain-in-the-ass than anything else. Basic filtering through glass wool
was more than enough for my needs. This was until I discovered ROOTO through my local
Ace Hardware. I'll never go back to Roebic ! If you want good sulphuric acid OTC, that's
the way to go ! BTW, Misty is an excellent brand also but harder to get.




Power comes from the barrel of a gun !
View user's profile View All Posts By User
Pyridinium
National Hazard
****




Posts: 258
Registered: 18-5-2005
Location: USA
Member Is Offline

Mood: cupric

[*] posted on 14-6-2005 at 21:21


BromicAcid, I have also noticed during recycling H2SO4 (contaminated with organic matter and metal ions), the conc. acid by itself will carbonize the organics and oxidize them after protracted heating at around 220-240 C. SO2 and water come off, as well as CO2 and H2SO4 fumes. It takes about a day of heating to make the acid turn from murky brown-black to pale straw-yellow.
I know it's a great deal of work and not really cost effective. Also dangerous.

side note... Oxidizers... :) You and the other regulars on this forum obviously know not to put permanganates or chlorates in the acid to oxidize the contaminants, but some occasional readers might not. So we might as well tell them now: DON'T use permanganates or chlorates for this.
View user's profile View All Posts By User
neutrino
International Hazard
*****




Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline

Mood: oscillating

[*] posted on 15-6-2005 at 02:26


Perchlorates also wouldn't be the best of ideas here.

In response to a previous question, the peroxide works by forming caro's acid (H<sub>2</sub>SO<sub>5</sub>;), which then oxidizes any organic matter present.
View user's profile View All Posts By User
Organikum
resurrected
*****




Posts: 2228
Registered: 12-10-2002
Location: Europe
Member Is Offline

Mood: fluffy!

[*] posted on 15-6-2005 at 04:25


A european brand of drain cleaner "STURA FACILE" says it is 66°Be H2SO4 what would be 94% to 98%. It has a reddish tint and foams when used as in in drying bottles or similar.

On heating to the boiling point it first turns black - after prolonged heating it turns almost perfectly clear.

My experieneces with battery acid 38% vary. Some stayed perfectly clear upon concentration and some got greenish - probably from iron salts present from storage in iron vessels.

/ORG




Restrict alcohol and Tobacco.
Legalize everything else.
Mandatory LSD for politicians and Franklyn.
View user's profile View All Posts By User
ADP
Hazard to Others
***




Posts: 120
Registered: 4-4-2005
Location: USA
Member Is Offline

Mood: Productive

[*] posted on 15-6-2005 at 10:01


Hmm I wonder what H2SO5 + KNO3 would yield. Or if the H2SO5 would just decomp and make Nitric acid and a salt.
View user's profile View All Posts By User
Scratch-
Hazard to Self
**




Posts: 60
Registered: 22-2-2005
Location: U.S.
Member Is Offline

Mood: No Mood

[*] posted on 15-6-2005 at 12:07


I was wondering something similar, I was wondering if H<sub>2</sub>SO<sub>5</sub> could be stabilized by adding NaOH or other strong base?

H<sub>2</sub>SO<sub>5</sub> + 2 NaOH => Na<sub>2</sub>SO<sub>5</sub> + 2 H<sub>2</sub>O
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
BromicAcid
International Hazard
*****




Posts: 3002
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline

Mood: Legitimate

[*] posted on 15-6-2005 at 16:46


Persulfates are fairly stable salts, ammonium persulfate being somewhat widely avalible for etching circuits.



Shamelessly plugging my attempts at writing fiction: http://www.robvincent.org
View user's profile Visit user's homepage View All Posts By User
neutrino
International Hazard
*****




Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline

Mood: oscillating

[*] posted on 15-6-2005 at 17:31


I think SO<sub>5</sub><sup>2-</sup> is more accurately called peroxysulfate. Persulfate (the etching ion) is S<sub>2</sub>O<sub>8</sub><sup>2-</sup>.
View user's profile View All Posts By User
Pyridinium
National Hazard
****




Posts: 258
Registered: 18-5-2005
Location: USA
Member Is Offline

Mood: cupric

[*] posted on 15-6-2005 at 18:32


I'm pretty sure one of the preparations for Caro's acid (peroxymonosulfuric acid) involves reacting persulfate (peroxydisulfate) with H2SO4.

Might've been mentioned in another thread, sorry if it's redundant.

I think in the cold (-80 C) you can get it to form crystals. They are stable as long as the temp doesn't rise...
View user's profile View All Posts By User
Bonome
Harmless
*




Posts: 6
Registered: 19-2-2008
Member Is Offline

Mood: No Mood

[*] posted on 25-2-2008 at 16:25
Purify sulfuric acid


Is it possible to remove the impurities of Sulfuric Drain Opener? I don't found any topics about the question and I think it would be great if we can find a solution to purify Drain Opener acid because it's inexpensive and personally I'm in canada and I really don't know how to obtain pure sulfuric acid. My idea was to Distill at very high temperature to break the acid to H2O and SO3 but the difference in temperature between the cold condenser and vapour will certainly brake it so maybe you have more idea?



There is no knowledge that is not power.
View user's profile View All Posts By User
bereal511
Hazard to Others
***




Posts: 162
Registered: 9-8-2005
Location: Madison, WI
Member Is Offline

Mood: No Mood

[*] posted on 25-2-2008 at 17:30


IIRC, there was a thread a while ago that discussed the use of hydrogen peroxide by slowly adding it to sulfuric acid drain cleaner and heating the solution gently, withsuccess in getting rid of most of the organics.



As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life -- so I became a scientist. This is like becoming an archbishop so you can meet girls.
-- Matt Cartmill
View user's profile View All Posts By User
BromicAcid
International Hazard
*****




Posts: 3002
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline

Mood: Legitimate

[*] posted on 25-2-2008 at 18:18


Yes there are other topics on this around here though I am not sure about what they are titled. Distillation will work, giving you the azeotrope of something in the neighborhood of 96% sulfuric acid. The peroxide method that bereal mentioned above noteably lightens darker sulfuric acid though that doesn't say anything for any cations/anions that may be present, just some of the organics. Anyway, there are other threads.

If you haven't found out yet our search engine here is somewhat shoddy so I recomend going to google and searching with the modifier

site:sciencemadness.org

which will give results from this site. There are a few threads covering this from various aspects so good luck.




Shamelessly plugging my attempts at writing fiction: http://www.robvincent.org
View user's profile Visit user's homepage View All Posts By User
Bonome
Harmless
*




Posts: 6
Registered: 19-2-2008
Member Is Offline

Mood: No Mood

[*] posted on 25-2-2008 at 18:54


Thanks, I found the topics.

titled 'cleaning sulfuric acid'

sorry for this double post maybe an administrator can delete mine?




There is no knowledge that is not power.
View user's profile View All Posts By User
chemrox
International Hazard
*****




Posts: 2901
Registered: 18-1-2007
Location: UTM
Member Is Offline

Mood: psychedelic

[*] posted on 25-2-2008 at 23:13


I made pirhana from drain cleaner and 30% H2O2. It cleared immediately on adding the peroxide. Ala Vogel 100% sulfuric is made by adding oleum (fuming acid) to the 98% which is obtained by distillation. I.e distill the drain cleaner and you've got reagent acid.



"Ignorance is the Mother of Devotion." — Robert Burton.
View user's profile View All Posts By User
Pulverulescent
International Hazard
*****




Posts: 792
Registered: 31-1-2008
Member Is Offline

Mood: Torn between two monikers ─ "hissingnoise" and the present incarnation!

[*] posted on 7-3-2008 at 04:42


The first time I boiled battery acid, I got a brown acid, which became colourless on prolonged heating. As the colour vanished, small bubbles appeared and a small white precipitate formed.
The precipitate was silica and the colour was caused by dissolved carbon which was subsequently oxidised by hot H2S04.
Silicon carbide, it seems, had been added to the acid to prevent the formation of long lead crystals on the battery plates, which could short the cells.
If the drain-cleaner contaminant was organic it would be fully oxidised by strong heating.
Adding peroxide is a waste since hot H2S04 itself, is a good oxidiser.
I've thought of getting an old-type retort and distilling draincleaner but there's a chance the contaminent would come over with the acid and I don't know if borosilicate would withstand heating to 337*C. . .
View user's profile View All Posts By User
MagicJigPipe
International Hazard
*****




Posts: 1553
Registered: 19-9-2007
Location: USA
Member Is Offline

Mood: Suspicious

[*] posted on 7-3-2008 at 06:26


"and I don't know if borosilicate would withstand heating to 337*C. . . "

It most certainly will. I boil sulfuric acid all the time and have never had problems. Never. Except for the very first time I did it. I didn't realize how hot the H2SO4 was (even nearly 45min after boiling) and poured it in a HDPE container. It melted and sprung a leak while I was holding it so I panicked, dropped it and hot sulfuric acid went everywhere. "Fuckin flying shitballs!", I exclaimed as I deficated in my pants. Just kidding about the defication.

What's funny is at the time, my parents, knowing nothing about chemistry or chemicals said, "Your jeans look like you spilled a bunch of battery acid on them!"

Anyway, I think I may have read about this here somewhere but has anyone attempted distillation of H2SO4? In theory, this should yield extremely pure acid even from drain cleaner. As far as dissolved solids go it should be like reagent grade as someone mentioned earlier.

I always wanted to try it but I don't want my glassware to break. I'm theorizing about a decent way to heat the neck of the flask so that no water drips into the acid. Any ideas other than a topside mantle?




"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
View user's profile View All Posts By User This user has MSN Messenger
-jeffB
Hazard to Others
***




Posts: 185
Registered: 6-12-2007
Member Is Offline

Mood: No Mood

[*] posted on 7-3-2008 at 07:42


I'm working up my nerve to try distilling some drain cleaner. In the past, I've distilled lower-boiling liquids in an all-glass setup where I wrapped Teflon tape around the male connectors during assembly. It looks like the upper temperature limit for standard Teflon tape is somewhere around 300C. How bad an idea would it be to use standard "plumber's" Teflon tape in this temperature regime?

I'm thinking a water-cooled condenser is also a bad idea. I have a straight tube with 24/40 connectors on each end that's maybe 60cm long. If I use that as my first stage, then have a standard water-cooled West or Liebig after it, I'm thinking that I'd get low overall thermal stress and good containment of hot acid vapor. Or is the water-cooled stage overkill?
View user's profile View All Posts By User
microcosmicus
National Hazard
****




Posts: 287
Registered: 31-12-2007
Member Is Offline

Mood: spin up

[*] posted on 7-3-2008 at 08:01


Glass (of any kind) will withstand heating up to its softening point without any ill effect ---
above that temperature, it begins to sag and gets softer as you heat beyond that point,
ultimately leaving you with a puddle of glass where your flask was. For both borosilicate
and soda-lime glass, that temperature is around 500C, so 337C is within the
capabilities of glass.

What wrecks glass is not heat, but thermal shock. As long as you take care to apply the
heat gradually and evenly and let the glassware cool back to room temperature gradually
and evenly, it won't crack if it isn't scratched and free form internal stress.
For what you are doing --- boiling a liquid --- the liquid acts as a heat bath and keeps
the temperature steady as long as you don't distill to dryness, which is a bad practice anyways.
The advantage of borosilicate glass is that it has a lower coefficient of expansion, so can cope
with larger thermal shocks before it goes kaput. With care, you can certainly distill your
H2SO4 in glass vessels just as it has been done since the time of Gerber.

MagicJigPipe, I'm glad there were legs still left within those wrecked pants ;)
I suppose that urination would at least serve to wash and neutralize
some of the spilt acid :P

[Edited on 7-3-2008 by microcosmicus]
View user's profile Visit user's homepage View All Posts By User
Pulverulescent
International Hazard
*****




Posts: 792
Registered: 31-1-2008
Member Is Offline

Mood: Torn between two monikers ─ "hissingnoise" and the present incarnation!

[*] posted on 7-3-2008 at 14:04


Yeah, for one thing, I'd worry that my condenser would crack, even as an air condenser.
No way would I have water in it. . .H2S04 vapours should condense easily because of the high boiling point.
I don't want to endanger an RBF, either, or overheat teflon(teflon flu'?)!
And, using no lube might end with seized joints.
I'd certainly try it with a good retort, if I had one. Even then, though, the side-arm might get too hot to condense the distillate.
Oh, and before distilling I'd try to make sure the water was boiled off first.
MJP, when I was a kid I stuck carbon rods into a jar of battery acid, connected to the mains and switched on. . .a green arc formed even though there was a half inch gap, and the acid fountained up and onto the floor. It was a polished wooden bedroom floor and I thought, "shit it's going to turn to sawdust in a few months, and then I'll get a major bollicking. Nothing happened the floor but I had a few scares when the word floor came up in conversation.
Let's just hope someone else does the distillation and tells us(tongue in cheek)here.
P
View user's profile View All Posts By User
Pulverulescent
International Hazard
*****




Posts: 792
Registered: 31-1-2008
Member Is Offline

Mood: Torn between two monikers ─ "hissingnoise" and the present incarnation!

[*] posted on 7-3-2008 at 14:50


Right now, I've got several litres of dirty acid. It's in a demijohn with rubber stopper. 'Thought rubber was ok, but it's disintegrating with time and now all this shit's sitting in the acid---in the middle of it.
I've just ordered a fritted funnel, though; should arrive any day.
If I want fresh acid, I'll electroplate copper from CuS04 sol..
An inert anode is soooooo useful---expensive but kinda essential, too.
P
View user's profile View All Posts By User
Armistice19
Hazard to Self
**




Posts: 87
Registered: 19-6-2007
Member Is Offline

Mood: Brain sponge activated!

[*] posted on 17-5-2008 at 09:11


I actually had a quick question, I just obtained a couple car batteries from a junk yard, They seemed to still contain at least very small amounts of acid as the liquid fizzled when it came in contact with the concrete in my backyard. I filtered the acid through coffee strainers. As the lead sulfate collected in the mesh of the paper, a clearer liquid dripped into the glass container, and I obtained an atleast somewhat purified weak acid. I then bought a small propane camp-cooking stove from a sports outlet in order to boil the acid (this was much cheaper than buying a laboratory hotplate at the time). I put a teflon skillet filled with cooking oil onto the flame, and a pyrex cooking glass full of the acid into this. After a while the acid began to boil so I went over to a friends house while another friend checked on the acid for me. When I returned I found a yellow oily liquid at the bottom of the pyrex glass just as I had wanted, but to my surprise it was not fuming. In fact, it was fuming less than it was when I was just boiling off the excess water. I then proceeded to pour a drop or two onto concrete... no fizzle. Not being stupid enough to try it on my own flesh I skipped that part and funneled it into a storage bottle, and tried again. I achieved the same result the second time, an oily, yellow, non-fuming, and apparently unreactive liquid. This time when I funneled it into its bottle a drop of it splattered out and touched my leg....no burn, nothing, just a warm oily liquid is all it apeared to be. What did I do wrong? Perhaps I boiled it too long and destroyed the acid?



“Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand.” -Albert Einstein
View user's profile View All Posts By User
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

[*] posted on 17-5-2008 at 10:05


Try diluting it with H2O. If it heats up and acts like an acid, good bet it is what it should be.

Tim




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
ADP
Hazard to Others
***




Posts: 120
Registered: 4-4-2005
Location: USA
Member Is Offline

Mood: Productive

[*] posted on 17-5-2008 at 10:46


I'm interested in attempting a vacuum distillation of sulfuric acid from drain cleaner. If I do this I'll take some pictures. Does anyone know where I can find a vapor pressure table for sulfuric acid?



View user's profile View All Posts By User
MagicJigPipe
International Hazard
*****




Posts: 1553
Registered: 19-9-2007
Location: USA
Member Is Offline

Mood: Suspicious

[*] posted on 17-5-2008 at 11:34


If it doesn't burn you instantly it is definitely not concentrated H2SO4. I got a pretty bad burn the other day from 35% sulfuric. Yes, it sat there for about 30 seconds but that's only 35%! Concentrated will char your skin instantly. Go to a hobby store (Hobby Lobby) and get some pH paper if you want to know for sure but I doubt you have any acid in there. How long did you boil it? It's possible that you boiled out all of the acid. Also, NEVER use "Pyrex" glass that you buy from Wal-Mart for chemistry purposes. It will go up to 320*C easily to boil sulfuric acid but once it cools down it WILL shatter. It IS NOT borosilicate.



"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
View user's profile View All Posts By User This user has MSN Messenger
Pulverulescent
International Hazard
*****




Posts: 792
Registered: 31-1-2008
Member Is Offline

Mood: Torn between two monikers ─ "hissingnoise" and the present incarnation!

[*] posted on 17-5-2008 at 14:05


Armistice 19, the cooking-oil may have contaminated the acid when its temperature reached a certain point.

The boiling temperature of H2S04, 339*C, might be high enough to cause the oil to boil and spatter into the acid.

If the glass was pyrex, you shouldn't have needed an oil-bath.

Careful monitoring and a fume-hood would have helped.

Slow heating, without the oil-bath would have given the result you wanted.

The residue you were left with may just have been the oil that spattered into the glass---the acid having been mostly driven off.

P
View user's profile View All Posts By User
 Pages:  1  2    4

  Go To Top