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Anthony
March 17th, 2003, 07:33 PM
the_wingman
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posted January 30, 2001 11:54 AM
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Has anybody ever tried to produce potassium perchlorate from potassium chlorate and sodium persulfate (sodium peroxodisulfate)?
Does it worth trying? thanx


J
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From: United Kingdom
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posted January 30, 2001 02:05 PM
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I have read that KClO3 may be converted to KClO4 by electrolysis of the solution. I think that the voltage must be maintained at 6.4v for hundreds of amp/hours.
J


blackadder
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posted January 30, 2001 02:10 PM
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Correct me If I'm wrong, but I read somewhere that you can get the perchlorate of a metal by adding perchloric acid to the hydroxide of that metal. So, to get potassium perchlorate, one would add perchloric acid to potassium hydroxide.


Mammut
A new voice
Posts: 39
From: Essen,NRW,Germany
Registered: JAN 2001
posted January 30, 2001 02:23 PM
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Hey
I´m sorry i have no tip for u, but i have
80% Perchlorate-acid and i say if u do ca.
5ml on a paper and give fire to it, little
stars and smoke u can see [very cool]!!


firebreether
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posted January 30, 2001 02:30 PM
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Thats how perchlorates are formed - by adding X OH to HClO4


kingspaz
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posted January 30, 2001 03:14 PM
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yer i read somwhere that u can melt potassium chlorate and it will react with oxygen in the air to form the perchlorate. If this is possible it could be difficult to melt the chlorate without it decomposing.


blackadder
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From: London
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posted January 30, 2001 04:03 PM
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Whoah, that sounds pretty simple. I'm guessing one would heat it over a low flame until it melts. Would there be any danger involved?


firebreether
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posted January 30, 2001 04:11 PM
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Are you really going to heat a chlorate over a flame???? Your crazy, most likely it would just bust out and burn away.


kingspaz
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From: UK
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posted January 30, 2001 04:38 PM
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well i haven't tried heating it and have no intention of trying to because chlorates decompose really easily. Pesonly to make pechlorates i would eletrolise sodium chlorate and which would give me sodium pechlorate then i would convert this to potassium pechlorate by reacting with losalt.


blackadder
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From: London
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posted January 30, 2001 04:43 PM
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Hey, hey, calm down!
I'm not crazy, I didn't mean just shove it over a flame, if that's what you thought. Anyway, looks like that idea's going to the trash...


kingspaz
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posted January 31, 2001 03:45 PM
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sorry.....i never ment to sound mad!!!


wantsomfet
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posted January 31, 2001 04:21 PM
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Potassiumchlorate will melt at ca. 356 deg. C and decompose at 400 and above. If molten it will take oxygen from the air and form KClO4. So if you have very, very pure KClO3 you could heat it (no flame of course) to exact that temperature an probably obtain KClO4. Questionable is how pure the KClO4 will be or how long it takes for a specific amount of KClO3 to convert to KClO4.
Note that the slightest impurities may cause decomposition = boom
I suggest only melting very little amounts...
Converting KClO3 electrolytically requires Pt-anode, Cu-cathode. 10V to 14V & 0,1 A/h per cm2 surface. For ~12g KClO3 in 200ml H2O it'll take ca. 3 hours, or set a higher power.
Another method is KClO3 and H2SO4 (sulphuric acid)at low temperatures, i have the info somewhere, if i find it i'll post it.
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Anthony
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From: England
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posted February 01, 2001 10:30 AM
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<a href="http://huizen.dds.nl/~wfvisser/EN/perchlorate_EN.html" target="_blank">http://huizen.dds.nl/~wfvisser/EN/perchlorate_EN.html</a>
You just have to hold it at it's melting temperature for a few hours.

The trouble with the electrolysis mehtod of forming perchlorates is making sure it has converted once it hasd formed, as it takes a long time.

The problem with using perchloric acid is that most human beings can't get it!


the_wingman
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posted February 01, 2001 02:08 PM
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But is there a possibility without the use of electrolysis cells or heating equipement?
I once read somewhere that mixing p. chlorate and sodium (or ammonium) persulfate with H2O and heating the solution would give potassium perchlorate.
I think it's because persulfate is a stronger oxidizer than perchlorate !?


PHILOU Zrealone
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posted February 02, 2001 07:58 AM
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Forming KClO4 from KClO3 (or the sodium salt) is simply a auto oxydoreduction:
KCLO3 + 3KClO3--&gt; KCl + 3 KClO4
Thus you should have if you do a 100% reaction (what is almost never the case) 3/4 of you starting KClO3 converted into KClO4; you willthen have 1/4 of KCl to take away by recristallisation.
Perchloric acid can be done by adding HCl conc (max 37%) to NaClO3 (solid) and reflux boil it gently for hours.
HCl is very volatile!!!!!
HCl + NaClO3&lt;===&gt; HClO3 + NaCl (cristallises out)
HClO3 + 3 HClO3 + heat and air--&gt; HCl + 3 HClO4.

Don't try mixing NaClO3 with a stronger acid like conc H2SO4 because HClO3 is an explosive acid when concentrated.
By distillation it is then possible to recover the HClO4 as a 79% solution (over the acid is explosive!!!!).

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PHILOU Zrealone
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posted February 02, 2001 08:02 AM
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NH4ClO3 is very prompt to self autooxydoreduction into a weird mix of dangerous compounds like NH4NO2, NH4NO3, NH4ClO2,NH4ClO, Cl2O, ClO2, NH4ClO4, NCl3,... the mix can decompose spontaneously even in solution and lead to ignition-explosions-detonations.
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"Life that deadly disease sexually transmitted".
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blackadder
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posted February 02, 2001 08:52 AM
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Yeah, those compounds seem to be quite dangerous, chlorine dioxide explodes on formation, this can be seen if you put some conc. H2S04 onto some KClo3.

vurr
April 28th, 2003, 06:47 PM
NH4ClO3explodes @ 102C,when dry. and maybe in extremly concentrated solutions.
when metal_ClO3 is low and ammonia(salts) is added slowly @ 105 C or up to perchlorate solution ,it should be not too dangerous to get rid of chlorate contamination..??

John Ashcroft
May 4th, 2003, 12:55 AM
It's not chlorine dioxide which explodes on formation; it's chlorine heptoxide (Cl2O5).

Marvin
May 5th, 2003, 08:39 PM
Ammonium chlorate has the same sort of autocatalyctic problem as sulphur chlorate mixtures. It can go off when it feels like it, but its much more likley on prolonged storage.

All the chlorine oxides can go off when they feel like it, or fairly reliably on contact with sulphuric acid/heat/light/organic compounds. Adding sulphuric acid to chlorates doesnt produce the heptoxide, you need perchlorates for that.

John Ashcroft
May 5th, 2003, 10:25 PM
Oops. "Heptoxide" should have been "pentoxide."

Marvin
May 6th, 2003, 09:38 PM
Chlorine doesnt have a pentoxide, the yellow explosive gas that forms when you add sulphuric acid to chlorates is the dioxide, though I forget what else forms to balence the redox. You are thinking of nitrogen chemistry possibly regarding the pentoxide, and the numbers would balence.

John Ashcroft
May 6th, 2003, 10:09 PM
It's not chlorine dioxide which explodes on formation; it's chlorine heptoxide (Cl2O5).

I corrected that to say "pentoxide." With the correction, what I said agrees with your statement - chlorine pentoxide isn't stable enough to exist (hence explodes on formation).

Marvin
May 10th, 2003, 04:38 PM
I dont think its fair to say something you cant make 'explodes on formation' simply becuase you cant make it. Or for that matter, why its relavent to the thread unless you are contradicting blackadders post, as I assumed.

What is exploding on formation in blackadders post is ClO2 as he stated, not the pentoxide.