Tdep
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Chlorite to chlorate
Ok so this is a pretty basic question, but I'd like a definite answer...
I can oxidise sodium chlorite to sodium chlorate with hydrogen peroxide yes? You can do this to go from nitrite to nitrate but is there something
different going on where it goes the other way and the chlorite goes to sodium chloride?
If hydrogen perxoide is no good, is there another common oxidiser that will do the trick? 
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PHILOU Zrealone
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NaOCl and NaOClO will do the trick under boiling without need for H2O2...
This is called disproportionation (an auto-oxydo-redox).
NaOCl + NaOCl --> NaCl + NaOClO
NaOCl + NaOClO --> NaCl + NaOClO2
So
3 NaOCl --> 2 NaCl + NaOClO2
This is why bleach has to remain cold and that electrolysis cell of NaCl for chlorate production is not cooled down.
[Edited on 26-6-2014 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Tdep
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I've done that many a time, mostly with shitty yields but that's been discussed before.
I'll rephrase the question.
I want chlorate and chlorite, but I only want to buy one bag of one for cost reasons.
Is it better to buy a bag of chlorite flakes and turn that into chlorate or better to buy a bag of chlorate and turn it into chlorite when I want it?
In terms of cost and ease of experiments.
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woelen
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In an amateur setting conversion of chlorite to chlorate and v.v. are not really easy, although it can be done. But performing the reaction, isolation
and purification will cost chemicals as well, so I think it is not worth the effort.
If I were you, I would buy the chlorite (this is much harder to make in an amateur setting) and I would make the chlorate in an electrolysis cell.
There are many threads on sciencemadness about construction and use of chlorate cells.
At the moment you could buy chlorite and chlorate from the same seller on eBay and only have to pay shipping costs once by combining in a single
shipment. Checkout this eBay link:
http://www.ebay.nl/sch/naclo2009/m.html?item=281360493764&am...
I myself have purchased sodium chlorite from this seller.
If your goal is pyrotechnics, then I want to warn you. Chlorite is more reactive than chlorate and is useless for pyrotechnic purposes! Mixes with
chlorite in it are fun on a mg-scale for nice spectacular demos, but storing such mixes and using them in pyrotechnic devices is plain madness, they
are too sensitive to be handled in more than mg quantities!
Even chlorate is insidious in pyrotechnics, there is enough written on sciencemadness about that subject as well.
[Edited on 27-6-14 by woelen]
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Tdep
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Never into anything serious with pyrotechnics, nor storing things (I'm a moody person, got to use the things when I make them or I might not get to it
for weeks) but it's always go to be reminded of that just because you can make something, doesn't mean you should.
Not worth the effort? That is disappointing, but I guess it's motivation to finally build a chlorate cell and and turn my bucket of KCl into some
lovely chlorate crystals.
He was the exact seller I was looking at, but it's not just money but all the govenment/posting things. Maybe i'm too paranoid but buying two large
parcels of oxidisers at once makes me worried about the consequences.
Thanks for the great reply as always, quality bloke
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AJKOER
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An interesting experiment, using Mg(ClO2)2, treat with air per an old source (see "The Manufacture of Sulphuric Acid and Alkali: Ammonia-soda, various
..." by Georg Lunge, an online googlebook, link: http://books.google.com/books?id=FnrTAAAAMAAJ&pg=PA669&a... ) to quote page 669:
"Now chlorine was passed into a milk of- magnesium hydroxide and water, at temperatures between o° and 100°. Even at 0°, together with magnesium
hypochlorite, much chlorate was formed, more than corresponding to half of the chlorine entering into the reaction. At 15° a little more chlorate was
formed, together with much hypochlorate, some of which was changed into chloride, with evolution of oxygen. In both solutions the hypochlorite is
easily converted into chlorate, not merely by heating to 50°, but even by prolonged agitation by a current of air at ordinary temperatures. At 70°
C, from the first mostly chlorate was formed, with a little chloride, produced by loss of oxygen. Hence magnesium hypochlorite in statu noscendi does
not possess much stability and is easily transformed into chlorate."
In the spirit of science madness (but actually with a basis in chemistry) treat Magnesium chlorite (or even Magnesium hypochlorite) with first a
hypochlorite (or HOCl) and then, add H2O2!!
Why? Becomes singlet oxygen is formed which is reputedly more active than plain oxygen (or air) ( see http://en.m.wikipedia.org/wiki/Singlet_oxygen ) based on the assumption of sensitivity to oxygen for Mg(ClO)2 per the dated source above. I also
have some limited experimental evidence in this case, so I, for one, would not be surprised if you reported better yield, at least for the Magnesium
salt.
Note, adding NaOH, and filtering out the Mg(OH)2, gets back to the Sodium salt.
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A related alternative route, employ Ozone, which would be more generally applicable on all chlorite salts. See, for example, http://www.sciencedirect.com/science/article/pii/00431354960...
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Note, air may work not due to O2, but CO2, which slowly forms HOCl with a hypochlorite.
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[Edit] One should also mention photochemistry, albeit a slower path. For example, an explanation as to perchlorate formation on a different world
(link: http://www.sciencemadness.org/talk/viewthread.php?tid=29522 ), to quote:
"An ongoing source of perchlorate formation would indicate the likely presence of other oxychlorine species during the oxidation of chloride to
perchlorate, such as ClO-, ClO2- and ClO2(g) as well as other possible radicals such as ●OCl, ●Cl, or ●OH. "
the later radicals forming during photolysis. This is, interesting, per one of prior threads (see report of success at http://www.sciencemadness.org/talk/viewthread.php?tid=27013 ), a real path to at least chlorates on earth with photolysis. The latter most likely
proceeding along the following paths involving the mentioned species ·Cl, ·OH and ·ClO:
Cl2 + hv --> 2 ·Cl
2 ·Cl + 2 HOCl --> 2 ·OH + 2 Cl2 (g)
2 ·OH + 2 HOCl --> 2 H2O + 2 ·ClO (forming, at most, one Cl2O2 as there are poisoning reaction paths)
Cl2O2 + HOCl --> HClO3 + Cl2(g)
[Edited on 27-6-2014 by AJKOER]
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Zyklon-A
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Here is a useful book on chlorite production:
Attachment: production-of-sodium-chlorite.pdf (1.5MB)
This file has been downloaded 539 times
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AJKOER
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Useful, but a bit dated I suspect. Also, my take on using ClO2 gas (explosion hazard) with zinc dust dispersed in water as a path to chlorite:
Not simply: 2 ClO2 + Zn ---) Zn(ClO2)2
But more likely, in my opinion:
Zn (as dust) + 2 H2O ---) Zn(OH)2 + 2 H*
2 ClO2 + H2O = HClO2 + HClO3
2 H* + HClO3 ---) HClO2 + H2O
Zn(OH)2 + 2 HClO2 ---) Zn(ClO2)2 + 2 H2O
among other reactions. That is, perhaps active hydrogen acting on the Zinc surface is causing the reduction. For a related recent reference on Zn/H2O
reduction see
http://www.beilstein-journals.org/bjoc/single/articleFullTex...
I doubt if this reaction results in solely chlorite formation and I would certainly limit, per the reaction above, the quantity of Zinc employed (see,
for example, http://books.google.com/books?pg=PA100&lpg=PA100&dq=... ). Interestingly, my implied net reaction per above, is identical to the author's.
Also, the hydrolysis of ClO2 is by no means as rapid as Chlorine and water although the presence of Zn/H2O and a hydroxide could move the reaction
along.
Caution: There are reports of the action of Zn dust and HClO3 as violent. Work with dilute solutions and in small quantities only.
[Edited on 29-6-2014 by AJKOER]
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