Amos
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Chlorine gas neutralization
I just acidified some sodium chromate solution with sulfuric acid in order to convert it into sodium dichromate. The solution had some leftover sodium
hypochlorite in this, and when I did this outside a surprising amount of chlorine smell still made its way into my garage through the open door
several feet away. I'm inside the house now but I'd like to try and get rid of any remaining chlorine in there. Should I assume it will react itself
away on metal surfaces in there, or should I try to get rid of it some way? Ventilation won't be an option until the morning.
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Brain&Force
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Maybe leaving out a sulfite or thiosulfate compound will work? Or even just leave a faucet running, as the chlorine may dissolve somewhat in the
water.
At the end of the day, simulating atoms doesn't beat working with the real things...
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Amos
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Quote: Originally posted by Brain&Force  | | Maybe leaving out a sulfite or thiosulfate compound will work? Or even just leave a faucet running, as the chlorine may dissolve somewhat in the
water. |
I've got water boiling on a hotplate in there, in an attempt to turn it into HCl. I'm just pretty scared of chlorine, it might come under the door to
my basement.
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bbartlog
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Ammonia does a fair job of neutralizing chlorine fumes.
The less you bet, the more you lose when you win.
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Amos
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I actually just generated some anhydrous ammonia in there; I'd much rather have that than chlorine. Whatever the cause, I can no longer smell chlorine
in there anymore, meaning it's unlikely that its at a hazardous level. Thanks for your help guys.
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Zyklon-A
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Don't use that to neutralize chlorine, as this reaction occurs:
Cl2 + 2 NH3 → NH4Cl + NH2Cl
Chloramine is much more toxic than chlorine. Of course the ammonia will absorb water from the air, and then it might just neutralize it in an
acid-base reaction, rather then the disproportion reaction above.
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Amos
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| Quote: Originally posted by Zyklon-A |
Don't use that to neutralize chlorine, as this reaction occurs:
Cl2 + 2 NH3 → NH4Cl + NH2Cl
Chloramine is much more toxic than chlorine. Of course the ammonia will absorb water from the air, and then it might just neutralize it in an
acid-base reaction, rather then the disproportion reaction above. |
Even though my problem is solved, I don't see why we shouldn't talk about what and what not to do should this happen to anyone else. I read that
chlorine can be fatal after just a few deep breaths at 0.1% concentration in air. Surely monochloramine can't be THAT dangerous, right?
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AJKOER
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In the future, add dilute H2O2 to the solution containing NaClO until the vigorous foaming stops. The oxygen formed is actually pleasant smelling.
Also, the odor of the hypochlorite/hypochlorous acid is removed, and no chlorine will be generated upon adding H2SO4.
To remove the smell of Cl2 (and also Cl2O), I find that steam offer some help (steam from dilute H2O2 probably is even better if feasible). The reason
is likely:
Cl2 + H2O = HCl + HOCl
HOCl + H2O2 ---) HCl + H2O+ O2 (g)
Or, on net:
Cl2 + H2O + H2O2 ---) 2 HCl + H2O + O2 (g)
thereby driving the normal equilibrium for chlorine water to the right with the release of gaseous oxygen.
[Edited on 7-10-2014 by AJKOER]
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macckone
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A more likely mechanism is that the hypochlorite is converted
to perchlorate. The perchlorate ion is not displaced by sulfuric
acid. The perchlorate is also stable in acid solution unlike
the hypochlorite ion. If insufficient hydrogen peroxide is
used the chlorate could be formed which is unstable
with acids.
*edit* Wiki is sometimes your friend
The actual mechanism is much simpler.
NaClO + H2O2 -> NaCl + H2O + O2
I imagine some hypochlorite is in fact converted to perchlorate
but this is would probably be the preferred reaction.
The bimolecular chlorine is unlikely to form in basic NaClO solution.
[Edited on 7-10-2014 by macckone]
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CuReUS
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| Quote: Originally posted by Zyklon-A |
Don't use that to neutralize chlorine, as this reaction occurs:
Cl2 + 2 NH3 → NH4Cl + NH2Cl
Chloramine is much more toxic than chlorine. Of course the ammonia will absorb water from the air, and then it might just neutralize it in an
acid-base reaction, rather then the disproportion reaction above. |
also the ammonium chloride will fill the room with a dense white fume
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CuReUS
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| Quote: Originally posted by No Tears Only Dreams Now | | Quote: Originally posted by Zyklon-A |
Don't use that to neutralize chlorine, as this reaction occurs:
Cl2 + 2 NH3 → NH4Cl + NH2Cl
Chloramine is much more toxic than chlorine. Of course the ammonia will absorb water from the air, and then it might just neutralize it in an
acid-base reaction, rather then the disproportion reaction above. |
Even though my problem is solved, I don't see why we shouldn't talk about what and what not to do should this happen to anyone else. I read that
chlorine can be fatal after just a few deep breaths at 0.1% concentration in air. Surely monochloramine can't be THAT dangerous, right?
|
chlorine is not that dangerous ,read bromic acid's story of being "chlorinated" and living to tell the tale
http://www.bromicacid.com/mistakes.htm
although your lungs will burn for a long time
i got nitrated(inhaled too much NO2 )once while trying to do my first nitration reaction,because i didnt use a fume hood or any sort of
protection
my lungs burned for five days
drinking coffee and taking antioxidants(lemon juice ,anything rich in vitamin C and E) helps to reduce the pain somewhat
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Amos
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| Quote: | chlorine is not that dangerous ,read bromic acid's story of being "chlorinated" and living to tell the tale
http://www.bromicacid.com/mistakes.htm
although your lungs will burn for a long time
i got nitrated(inhaled too much NO2 )once while trying to do my first nitration reaction,because i didnt use a fume hood or any sort of
protection
my lungs burned for five days
drinking coffee and taking antioxidants(lemon juice ,anything rich in vitamin C and E) helps to reduce the pain somewhat |
Wow, compared to BromicAcid in his youth I feel like a freakin' professional. That is pretty reassuring, as I imagine at most I only generated a
couple of grams of Cl2. It's good to work with dilute things first before you step it up(As soon as my SS spoon is finished dissolving I will be
making sodium dichromate out of the whole thing)
[Edited on 10-8-2014 by No Tears Only Dreams Now]
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blargish
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| Quote: Originally posted by CuReUS |
i got nitrated(inhaled too much NO2 )once while trying to do my first nitration reaction,because i didnt use a fume hood or any sort of
protection
my lungs burned for five days
drinking coffee and taking antioxidants(lemon juice ,anything rich in vitamin C and E) helps to reduce the pain somewhat |
NO2 is no fun at all. I inhaled quite a bit more than I should have the first time I synthesized fuming nitric acid and tested the
product... Was sick for a week.
Chlorine is not as bad, as I have heard it has a good warning level (the point at which you begin coughing and feeling uncomfortable coincides with
the point at which you should get the heck out of there), as opposed to NO2, which is pretty bad at almost any threshold.
BLaRgISH
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CuReUS
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| Quote: Originally posted by Zyklon-A |
Don't use that to neutralize chlorine, as this reaction occurs:
Cl2 + 2 NH3 → NH4Cl + NH2Cl
Chloramine is much more toxic than chlorine. Of course the ammonia will absorb water from the air, and then it might just neutralize it in an
acid-base reaction, rather then the disproportion reaction above. |
but according to this wiki page http://en.wikipedia.org/wiki/Respirator under chemical warfare
during word war 1 ,when germans released chlorine gas into the trenches,a canadian soldier(he was actually a doctor) told the soldiers to hold urine
soaked cloth to cover their nose and mouth ,he though that chlorine would react with the ammonia in the urine and get neutralised.then if chloramine
is toxic,the soldiers would have died
although i have read somewhere else that will form dichlorourea so i am not sure
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xfusion44
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| Quote: Originally posted by blargish | | Quote: Originally posted by CuReUS |
i got nitrated(inhaled too much NO2 )once while trying to do my first nitration reaction,because i didnt use a fume hood or any sort of
protection
my lungs burned for five days
drinking coffee and taking antioxidants(lemon juice ,anything rich in vitamin C and E) helps to reduce the pain somewhat |
NO2 is no fun at all. I inhaled quite a bit more than I should have the first time I synthesized fuming nitric acid and tested the
product... Was sick for a week.
Chlorine is not as bad, as I have heard it has a good warning level (the point at which you begin coughing and feeling uncomfortable coincides with
the point at which you should get the heck out of there), as opposed to NO2, which is pretty bad at almost any threshold.
|
Well, with both Cl2 and NO2 I have some bad experiences I've done everything outside, except some electrolysis of brine. I can't say which would be
more toxic, but it happened to me, that I inhaled too much of both of them and neither was fun, but this happened to me more times with chlorine, so I
may think, that the chlorine is more nasty than nitrogen dioxide. Other than smell, experience was pretty much the same (burning in nose, throat,
coughing...) This happens, when Cl2 or NO2 reacts with water in throat and nose to produce HCl or HNO3, that's why it burns... If you inhale too much,
it becomes too acidic in lungs and lungs try to adjust the pH with more liquid (water I think, but I'm not sure), when this happens, you can drown in
your own liquid if breathing of those gasses isn't stopped soon enough. Once it happened to me, that I inhaled a lot of chlorine, while doing
electrolysis of brine (I wasn't sure that it works and I sticked my nose into the beaker ), than I coughed for an hour and It burned extremely when I inhaled it
Regarding of this topic I think it would help spraying the water in the room where chlorine is (so that it would react with it).
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AJKOER
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| Quote: Originally posted by Zyklon-A |
Don't use that to neutralize chlorine, as this reaction occurs:
Cl2 + 2 NH3 → NH4Cl + NH2Cl
Chloramine is much more toxic than chlorine. Of course the ammonia will absorb water from the air, and then it might just neutralize it in an
acid-base reaction, rather then the disproportion reaction above. |
Reading the current Wikipedia article on NH2Cl (link: http://en.m.wikipedia.org/wiki/NH2Cl ) appears to profess its great benefit over Cl2 as a water purification agent. This claim is not fully
supported, in my opinion, as while Chloramine does have a higher half life in the water supply, the claim of reduced tendency to produce
chlorocarbons, is perhaps dubious as the safest way to reduce THMs, according to the World Health Organization (WHO), is to remove the organic matter
from the water first through prefiltration before disinfection. Also, Chloramine is known to be much weaker/less effective disinfectant than Chlorine
to begin with (see another perspective on Chloramine at http://www.chloramine.org/chloraminefacts.htm ) especially with respect to viruses. The Wikipedia article does, with some balance, report the
increase in Pb absorption by Chloramine and possible fatalities from Lead with children.
My prior readings on Chloramine gives some insight of the elevated poisonous behavior with respect to Lead. Apparently, NH2Cl can magnified poisonous
properties (as to how precisely this is effected, I will let biochemist comment). There was a cited example of the accidental mixing of chlorine
bleach and ammonia in a factory setting (forming NH2Cl) in contact with Methyl alcohol, whereupon a mass blinding of workers ensured. Normally, such
exposure to CH3OH vapors will not blind one rapidly. Also, with the recent increase of unwanted nitrates (various American States post warning on the
web relating to particular dangers to newborns with respect to nitrates) and chlorates in the water supply (thanks apparently to the photocatalytic
ability of nitrates acting on Hypochlorous acid), NH2Cl may be a more problematic purification agent (in my opinion, as on hydrolysis, it forms NH3
and notably HOCl, which, with its extended life span, is potentially more likely to actually undergo photolysis forming chlorates).
Interestingly, not another reference in Wikipedia to its potential poisonous behavior until the very end of the relatively long article where to
quote:
"Chloramine has been implicated as a mutagen and as a toxic agent for aquatic life, hence the US EPA proposes to prohibit its use in drinking
water.[4]"
where, after tauting the script of politicians pushing it as a superior water chlorinating agent (over the very vocal, at times, public disapproval of
the substance), some lip service is served up to the interest of the fishing industry as it apparently is quite fatal to fish and marine life (as I
understand it, via the disruption of the biochemistry of oxygen absorption from the water, with a similar effect on gaseous oxygen absorption by red
blood cells for humans, per the prior link.) As such, reports on the increase/aggravation of respiratory illness by Chloramine treated swimming pools
(again, prior link) should not be surprising.
I find amusing the current Wikipedia article as I remember what the old Wikipedia article use to say, before its limited implementation as a water
purification agent. It was really scary stuff per my recollection. Also curiously, many MSDSs on NH2Cl, citing its toxic nature, appear to have just
vanished over time.
[Edited on 1-11-2014 by AJKOER]
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