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Making Potassium Chlorate

by mrjeffy321
Tags: chlorate, potassium
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Letda
#91
Jun19-05, 02:49 AM
P: 12
I guess Iím kinda of an unusual person, Iím a psychology major with a weird fascination with astrophysiology and aeronomics, so I guess Iím not trying to make "just" fireworks for the 4th of July but I want to use concepts from these basic principles to further my know how in such matters....

So, when boiling the bleach, do you just boil until no liquid is left or do you get the crystals before that, and are they what I need in pyrotechnics? And Iím totally unfamiliar with electrolytic, is that just like putting a positive charge on one end of the cup and neg. on the other end??? As you can see, at 17, I think I'm a little behind, I was too cool to take chem. serious in school.... how sad huh!
mrjeffy321
#92
Jun19-05, 04:49 AM
Sci Advisor
P: 882
The bleach boiling method is easiest to understand.
Bleach is a solution NaOCl (sodium hypochlorite), and generally it has alot of other stuff in there too, I know that clorox bleach is 6% NaOCl, 5.63% NaCl, and .015% NaOH, and the rest it is just inert stuff and/or water. All you are concerned with right now is the NaOCl.
When you boil bleach, the NaOCl decomposes to form NaClO3 and NaCl,
3NaClO --> NaClO3 + 2NaCl
Sodium hypochlorite is very soluble in water (100 g / 100 mL), but sodium Chloride not so much by comparison. So the trick is getting the maximum possible amount of NaClO3 dissolved in the smallest amount of water possible and not have very much "other" stuff in solution, like NaCl.

This page,
http://www.wfvisser.dds.nl/EN/chlora...therm_starting
gives instructions on how to make chlorate both using electrolysis and thermal decomposition of hypochlorites.

You will see in those instructions that you are suppose to boil 1 L of 4% bleach down to 140 mL. If you do the math (and I have), you will find that this is alot more than is really necesary to hold the amount of NaClO3 you will have left after decomposing the NaOCl. The reason is because there is all that other stuff in solution too. Actually, in practice, if you follow those instructions, there will be NaCl comming out of solution even before your done boiling.

Anyway, so now you have a solution of NaClO3 and some NaCl. But you wanted KClO3, not NaClO3!! to turn the sodium chlorate into potassium chlorate, you can use a double replacement reaction between the NaClO3 and KCl. The potassium ion will push the Sodium out of the NaClO3 and replace it, and then the Na ion will join up with the Chlorine ion,
NaClO3 + KCl --> KClO3 + NaCl

After you do this, you should notice a white percipitate forming. This because unlike NaClO3, KClO3 is not nearly as soluble, not even close.
But to maximize yeild, we want to get all the KClO3 out that we can, so we cool the solution down to just around 0 degrees celcius, and then filter out the percipitate, which will be mostly KClO3 and some NaCl.


The Key to the whole reaction is that bleach (NaOCl) will decompose and form NaClO3, which can them be turned into KClO3.

the electrolytic method is much more complex, but is explained in the web page provided above.
Letda
#93
Jun19-05, 01:45 PM
P: 12
I understand this alot better than before, so thnx. But, where do you get potassium chloride, is that the salt substitute? and is the NaCLO3 worth anything in that form or must the Na be replaced with the K?
mrjeffy321
#94
Jun19-05, 04:15 PM
Sci Advisor
P: 882
I buy my Potassium Chloride as a salt substitute, called, "NoSalt", there are also salt substitutes (I think called "LoSalt"), but these also contain a large part sodium chloride, you want to get the one with as much potassium chloride as possible.
Sodium Chlorate is in itself worth something. It will react very similar to KClO3, but because of its high solubility, it is hard to extract. alot of the time in chemical formulas for pyrotechnic things, KClO3 and NaClO3 are interchangeable.
Letda
#95
Jun19-05, 04:49 PM
P: 12
so let me make sure im understanding this. When you boil the bleach, you get NaClO3 crystals after filtering the liquid, or is the liquide the NaClO3?
mrjeffy321
#96
Jun19-05, 07:39 PM
Sci Advisor
P: 882
by boiling bleach, you make NaClO3 AND NaCl.
Since NaClO3 is so much more soluble than NaCl, most (or all) of the crystals that percipitate out will be NaCl, and the NaClO3 will remain in solution.

Then when you add KCl, you make KClO3 and NaCl. this time NaCl is much more soluble than KClO3, so most of the percipitate is KClO3 and then NaCl remains in solution.
Letda
#97
Jun20-05, 12:52 AM
P: 12
Thnx,i just bought everthing 10 mins ago so ill be testing everything tomorrow, ill let you knogw how things o. thnx for all of the help.
Letda
#98
Jun20-05, 12:27 PM
P: 12
well, my first run was a complete and utter failure....all i got was a bunch of brown and black stuff. I filtered it out, added the KCl and recooked...same thing...and i got no noticable crystals the first time? i guess ill start round two here in a bit...any suggestions?
Letda
#99
Jun20-05, 03:09 PM
P: 12
ok, i managed to get KCl pure crystals using the boiling process, but i dont know how the bleach is suppposed to work, i boil and all i get is a bunch of brown and balck crap. no crystals form, im i boiling to much or not enought or what?
mrjeffy321
#100
Jun20-05, 03:48 PM
Sci Advisor
P: 882
Are you following the instructions in the link I provided a couple posts back,
http://www.wfvisser.dds.nl/EN/chlora...therm_starting
I found if you follow these instructions pretty closely, you will have very good results, although some deviation can be made to see what works best.

You should boil the bleach in a pyrex / heat resistant glass container optinumy, definatly not metal.
Letda
#101
Jun20-05, 03:57 PM
P: 12
i was using metal, it said stainless steel on the site if i remeber right. i guess ill get glass then. Ill get back to you when i use the glass.
mrjeffy321
#102
Jun20-05, 09:15 PM
Sci Advisor
P: 882
I used to use stainless steel, and I kept getting some brown stuff in the mix while boiling. At first I thought it was a product from the reaction, although I couldnt explain what it was, and now I realize that it was most likely Iron Oxide being made when the bleach oxidized the Iron in the pan (my first clue is when it ate throught the pan and I had a big hole in it).

Glass is definatly best, although you need to be more careful with it. I use a old coffee pot that can take the heat.
Letda
#103
Jun21-05, 03:40 AM
P: 12
i just bought some glass bake-ware, hopefuly if i dont heat it up too fast it wont shatter. I mean if all else fails... I have on old coffee pot of my own so i can further follow in the steps of my mentor...lol.

you wouldn't happen to have anymore vidoes would you? I'm curiuos to see what you've been doing with 9 months supply. =)
mrjeffy321
#104
Jun21-05, 05:56 PM
Sci Advisor
P: 882
Any more videos? how did you know about those?....o wait, I remember posting those 2 videos to show the difference in flame color of the two batches of KClO3.
I do have a few more of some interesting stuff I did with the KClO3 (ending dramatically on Febuary 18th), but they are too large to show.

Now, I mostly just use it in small (less than 50 grams) pyrotechnic things. Right now, my stock pile is a little less than 200 grams of KClO3. Hopefully I can get my electrolytic cell up and working again.
redwraith94
#105
Jun21-05, 11:12 PM
P: 42
I was going to try the electrolytic cell myself, but after reading one of the links that you posted mrjeffy321, I decided to do the bleach method instead. I have tried the electrolytic methid before w/ Sodium chloride, and never was able to spend money for proper electrodes, so it always ended up something that I wasn't happy with. I just bought a gallon of the cheapest bleach that I could find. I'll keep you guys posted on how it goes.
Letda
#106
Jun22-05, 03:19 AM
P: 12
well, i just wanted to let you know the glass worked wonders and i got exactly what i was looking for but....in the midst of all of my happiness, while cooling off....it shattered. i was so disappointed to say the least. Now i cant find anything anywhere to use thats glass and can go on the stove. if you know of anybrand or place to buy it i would be more than happy to hear about it.

OH, and good luck to you redwraith94, its kind of a pain in the butt, but im sure youll have no promblems once you get going.
mrjeffy321
#107
Jun22-05, 03:46 AM
Sci Advisor
P: 882
Quote Quote by Letda
but....in the midst of all of my happiness, while cooling off....it shattered.
Oh no, I feel your pain.

Like I said before, I use an old [easily 15 to 20 years old] coffee pot, and as long as I treat it carefully, it works very well. Now-a-days, I dont think they make coffee pots as good as used to, alot of the ones I see say specifically not to boil water in them, and others NOT FOR STOVETOP USE.
Supposidly, Pyrex brand glassware is good for this type of thing, but even that must be made in different "Grades" of heat resistivity because all the pyrex I see in the store has that "Not For Stovetop Use" warning on them.
there are laboratory glassware peices designed to withstand high temperature conditions, that might be a possibility.
Letda
#108
Jun22-05, 09:33 PM
P: 12
My experiments are going to be post-poned for today at least, and probably tomorrow due to an unexpected direct assult from the flu virus...lol. but, not to worry, progress will presume soon enough and you'll know all aoubt it.


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