What Went Wrong in My Attempt to Make Potassium Chlorate?

[pack_rat2]

...but if you have a less then concentrated solution of KCl, then whrn you add it to the NaOCl, it will dilute the sodium hypochlorite solution more than necesary...

Note that you're not (ideally) adding KCl to a hypochloritel solution--the NaOCl, or most of it, should have been converted to NaClO3. I think the best approach is to take the most concentrated NaOCl sol'n you can make and thermally decompose it to NaClO3. Then dissolve the stoichiometric amount--plus some extra--of KCl in the minimum amount of water possible, and add it to the previous solution.

 

[mrjeffy321]

and thermally decompose it to NaClO3.

When I heat up and boil the hypochlorite solution, I am actually making sodium chlorate? for some reason I though I was making sodium chloride and oxygen gas (aside from the smell), that seemed to make more sense to me. but I do have experimental evidence to prove you are correct, some where, way up there in one of the ealier posts, I descibe a "mystery substance" that I believe to be sodium chlorate (you can ready my reasons on how I came to that conclusion if you can find the post) and I thought at the time that I had not added any potassium chloride to it (therefore keeping the sodium chlorate that I already had).
that would make perfect sense...I am destroying the bleach/sodium hypochlorite to make sodium chlorate.
Well, if that is true, than why the heck am I trying to keep it bleach for as long as possible with this slow heating idea, ...toss that out the window?


althought that solves one problem, maybe you can solve another I have had lingering.
when I first boil the bleach vigorasly for the first time, it starts forming this dark brown percipitate, I can filter it out, and I think it doesn't comeback if I boil the bleach again (dont remember exactly). I can't figure out what this brown stuff is, I asked clorox what the ingredients of their bleach were, and it didnt seem like anything unusual (although they never address the question concerning the brown stuff). the stuff won't react with anything that I have tried (ie. with the sugar that I react the chlorate with) and when you filter it out and dry it, it looks like rust almost.
any ideas?
what I could do is boil the bleach a bunch, and get the brown stuff out of it, while at the same time making sodium chlorate, so I kill to birds with one stone in that step, otherwise I have all this brown inpurity with my chlorate.

 

[pack_rat2]

I found some interesting info in a treatise on inorganic chemistry by Mellor. He doesn't mention decomposition of hypochlorites as a method for making chlorates, but describes the process in the hypochlorite section. Quite a bit of reseach has been done on it, mainly with the goal of PREVENTING it. Hypochlorous acid and hypochlorites undergo the following routes when they decompose: 2HOCl -> 2HCl + O2, 3HOCl -> 2HCl + HClO3. The first is the reaction that occurs when it produces bleaching action (oxidation by the O2) and is therefore the one usually desired. But I gleaned the following useful info... For a solution of NaOCl, chlorate generation is maximized at a pH of 7.13. Also, the presence of Na3PO4 is catalytic (he doesn't give a concentration, though). Other ions, including Cl(-) are catalysts, too, to a lesser extent. You might try starting with the strongest NaOCl sol'n you can buy (Clorox sells a high-potency version of their bleach that might be good). Then add ~1% Na3PO4 (just a wild guess for the amount), and adjust the pH with HCl (the sol'n will initially be very basic). You can get pH paper from any lab equipment supplier. Neutral to slightly alkaline ought to be good. You may have to be quick in checking the pH paper, since it will probably get bleached white pretty fast. As for the brown precipitate, it would have to be from an impurity or an unlisted ingredient. The presence of transition group cations (Fe, Cr, Mn, etc.) might do it, or it could be an organic. Be sure to do the boiling in a glass container; steel could add Fe.

 

[mrjeffy321]

As for the brown precipitate, it would have to be from an impurity or an unlisted ingredient. The presence of transition group cations (Fe, Cr, Mn, etc.) might do it, or it could be an organic. Be sure to do the boiling in a glass container; steel could add Fe.

(Fe, Cr, Mn, etc.), huh, well then a stainless steel pot wouldn't be the best thing to do it in, lol, that is what I have been using, that was originally my guess of what was causing it, but was dissuaded by many people saying, "O stainless steel won't react with it, that couldn't be the source of your problem, ...".

Can glass take the heat, obviously not normal glass, your talking about that special pyrex glass right, isn't that th stuff in measuring cups I think, where can I get some? would just any store have it in the kitchen/cooking section?

Quite a bit of reseach has been done on it, mainly with the goal of PREVENTING it

how funny.

OK I will put these new suggestions into practice and see what becomes of them.

 

[pack_rat2]

Pyrex glass is what I was thinking of. You can get all kinds of Pyrex bowls, pots, etc, made by companies like Corning, from department stores. Just one caution: even Pyrex can crack if it's heated too quickly by an open flame. So bring up the heat gradually.

 

[mrjeffy321]

Well, I still don't have any pyrex yet, but I did boil down a lot of bleach and make another attemp at chlorate.
this experiment took place over about 2 weeks, so I don't really remember any more the exact amounts of everything I used any more, but I think I was around 1 liter of bleach (which I boiled down to around 600), and a bunch of potassium chloride.

I haven't finished it yet, I haven't filtered out the stuff at the bottom and dried it out, but here is the interesting part, I have this concentrated bleach solution, I boil that and add a bunch a potassium chloride, mix it up thoughouly,...wait, cool it down in my refrigerator for 2 days and see what percipitates, nothing!, not exactly nothing, but the only thing that percipitated was a coupld little impurity particles things that passed through the filter I used right after I boiled it, so I decide the filter that out and putit back in the refrigerator for another day, so I do.
the next day what do I see? a bunch a white granuals (and crystal looking things) at the bottom of the bottle, mind you all I did to it was filter it once to remove those tiny little umpurites, nothing else, it didnt even warm up very much while filtering it.
so now I potentially have some chlorate, and probably chloride, at the bottom of my bottle, why is it just not getting around to percipitating out, why not yesterday, or the day before?

 

[pack_rat2]

...o now I potentially have some chlorate, and probably chloride, at the bottom of my bottle, why is it just not getting around to percipitating out, why not yesterday, or the day before?

I don't think there's any KCl, since it's too soluble. I think maybe it cooled down more, the second time, but I'm not sure.

 

[Dinner]

I am trying to make sodium chlorate (don't ask me why) by electrolysing a solution of table salt. I'm using a graphite anode and a stainless steel cathode. When I start electrolysing the solution an orange-brown precipitate forms (much like MrJeffy's). I looked at the ingredients of the salt I was using and it had Potassium Iodide in it! This, I think, would produce triiodide ions (and then iodine?) and is probably what causes the precipitate. Will this affect the formation of chlorate ions?

 

[mrjeffy321]

well the percipitate I got when trying to make chlorate through electrolysis was white, and I think we semi-determined that it was due to the impurities in the water (like floride, ...) and then it stopped occurring once all that stuff was used up and the water remained relativly clear.


for your table salt (mostly NaCl), there is indeed some potassium Iodide (KI) in it, but hardly any, I mean something around the order of .002% by wieght I think. so if you had a hypothetical amount of let's say 100 grams of salt dissolved in water, you would only have .2 grams of KI, and that is only about .0012 moles. so this is really, not very significant, not to say that it couldn't indeed be the cause of your problem, but I doubt that it is. plus, iodine/iodide compounds (at least the ones I know) are usually dark purple/blue/back, not orange-brown.


since you are using a stainless steel electrode (cathode) I am inclined to think that that is the cause of the percipitate, even though it is the cathode, it will corode slightly, but not nearly as much as the anode might.
I try to steer away from using any type of Iron (which includes(stainless)steel) in my electrolytic cells, it never ends well for the electrode.

try it with a graphite cathode as well as a graphite anode, and see if there is still some percipitate, also try using disstiled water insted of tap water if you arent allready doing that.

 

[mrjeffy321]

just an update on the status of that last batch of hlorate.

I had high hopes for this bacth, and it looked as if I was going to get a lot (comparitively) this time, and when I dried it out, it looked good. but when I tested it...
yellow (and slight, barely noticcible green) flame, the tale tell sign of sodium chlorate. Not that I don't like sodium chlorate, but it is just not what I am trying to make, especially after I add al that potassium chloride to the mix, and then nothing happens. I really need to get some pyrex I suppose to try this.


speaking of pyrex, I was at the store today looking at some pyrex cups I could use, and they say specifically on them, "not to be used on stove top, breakage may occur". it this warning just for stupid people who try to heat up an empty cup over an open flame, or should I actually follow this because it will break if I try to boil bleach in it, I think it is the former, right?

 

[pack_rat2]

First of all, I should point out that the slightest trace of sodium ions will cause a yellow flame, and it will mask the violet of the potassium. Second, you say "green"...hmmm. I think that's from free chlorine gas that comes from undecomposed hypochlorite. What you have can't be NaClO3 if it precipitates out from any significant volume of water. NaClO3 is EXTREMELY soluble.

 

[mrjeffy321]

so your saying, the sodium will easily cover up the potassium color, even if I just have a little.
which makes that previous instance of the violet burning powder potassium chlorate all the more special because it must be very pure.

there is just a little green, the vast majority of the color yellow.

acording to MSDS, NaOCl solution is "100 % solubile in water", but that doesn't mean that when the water is evaporating off the crystals in the filter, some isn't left behind, although it is odd that there still would be NaOCl left, after all that boiling and reacting.

I was experimenting with containers I could boil my stuff in, I tried an aluminum soda can, and it worked surpisingly well, considering its very small surface area in contact with the stove. it didnt corode, although the thnk plastic film coating the inside did come off.

 

[pack_rat2]

I was experimenting with containers I could boil my stuff in, I tried an aluminum soda can...

Just be aware that NaOCl is a strong base, and bases react with Al to form aluminates, with the evolution of H2. If no gas bubbles form, you're OK. Those cans often have an invisible plastic coating which protects the surface.

 

[mrjeffy321]

and bases react with Al to form aluminates, with the evolution of H2.

O really, I didnt know that, cool, I learned something new today.

If no gas bubbles form, you're OK.

well no, hydrogen gas bubbles formed (that I know of), but hopefully a lot of steam gas bubbles formed, hard to tell what it was, but the only danger I see of making hydrogen gas is the possibility of it combusting, and this isn't likely with the tiny amount I might have made.

Those cans often have an invisible plastic coating which protects the surface.

these do, although I think, not sure, that some of the coating came off while boiling, because it was bubling up from the can with all the gas forming around it, but I can't find any peices of it now.


I cooled that stuff down, and WOW, I got a lot of crystals, filtered then and put it back into the refrigerator, and checked again, WOW, another large second batch, so I filtered those. they are still drying, so no word on how it will come out yet. but I don't think I want to use aluminum cans any more, for the reasons you said, but also because it can hold very much liquid and it had vertually no contacting surface area with the stove, so it takes forever to heat up, and a high center of gravity, as conpared to a pot for example (spills waiting to happen, not something I need). and I am now werry of using pryrex on the stove (because of its warning label descibed above), are there diferent grades/strengths of pyrex? some mroe suited for my purposes/laboratory pruposes?

 

[mrjeffy321]

A coffee pot seems to work for a pyrex substitute, if it isn't already pyrex (it doesn't say), i boiled a lot of liquids in it, and I got a lot of crystals, but I think the stuff I am getting now is less pure than what i was getting before.
the crystals are harder and don't crush into as fine of a powder as they once did, and it is harder to light.
I am probably boiling away too much liquid, so that the salts cannot dissolve and percipitate out too, that is what I am thinking.

 

[pack_rat2]

Remember that NaClO3, which is what you're making by the decomposition of NaOCl, is very soluble. So is KCl. When you add the KCl sol'n to the NaClO3 sol'n, the relatively insoluble KClO3 precipitates out. You want the initial NaClO3 and KCl solutions to be as concentrated as possible (though not super-saturated).

 

[mrjeffy321]

I seem to be getting very good at making a chlorate that burns yellow now, I can make batches of around 10-15 grams at a time of a fine white powerder that burns yellow (and just a slight tint of green).

With another two batches under my belt that work as described above, I am really getting good at this, with less than compleate satifaction.
It is obviously not pure enough (or the right type) to burn the correct color, and it is rather time and space consuming to make it. Also, as a matter of interest, i took a quick trip out to the power meter outside and checked to see how significant a dent in the electric bill my electric stove is making now that it is running much much more than it is ever used, and a surprizingly fast and noticable change in the spin of the dial.


What about this as a way of purifying the product, set the crushed powder in a finter and slowly pour a small amount of cold water over it (volume of wate varies with amount of chlorate), the cold water won't dissolve much chlorate, in theory, and should remove the sodium, chlorine, ... impurities that is present.
This idea is similar to the suggested process that was given in the instruction of making the chlorate, but I am afraid of loosing to much in the process due to it dissolving away, despite its low solubility.

 

[Sparkee]

chlorate production

Hi,new member here! I have had some success with chlorate production by electrolysis using an old computer supply and carbon arc rods. Most of the information I gleened from the web. Visser's site being one of them,another site was rouge science(no longer available?) The power supply, the amount of solution, how many rods,etc... all were contributing factors. To the amount and how long it took to process. Not to mention that once you obtain the NaCLO3?? a double replacement reaction is necessary to obtain KCLO3. One of the test I used was combining the dryed KCLO3 with powdered sugar and adding a small amount of H2SO4. If you get a reaction the concentration is supposed to be above 20%Caution! It will happen fast! In your face fast if proper care is not taken! If I can be of help let me know. If the Chemistry is wrog please excuse me as I'am an Electrican not a chemist.

 

[mrjeffy321]

Hi, glad you decided to contribute to my thread.
you probably haven't read all my prior posts on this subject, but I did try the electrolysis method once, but I became very discurages with it due to the long hours of just waiting for it, ..., then I started having problems with the current jumping from high to low and then nothing at all, then I burned out some power supplies and ruined some batteries, and to top it off, I spilled the jar loosing half the solution! I had some really bad luck, and I didnt like just wasting all that hydrogen (I used to make and collect a lot of hydrogen a few months ago for some hydrogen detenations and for my fuel cell I buil, before I upgraded to some real explosives), and I also has problems with the (graphite) electrodes and the wires attatched to them clouding up my solution.
but it is nice to know that, with a little luck, other people seem to have great success with it.
One nice thing I found was a program on the internet that would save me a lot of time a guess work, insted of me working out how much salt, ... how long to run the cell, ..., you just input your starting conditions into the program, and it will compute it for you.
I do want to go back to the electrolysis method again, that is the more efficient and less labor intensive way of doing it(and cheaper), but I am currently out of supplies to do it with, I burnt out my last good power supply I can afford to loose, I still need to work out a better method for the electrodes, and Idealy for easily capturing the hydrogen gas (but that isn't necesary, just something that would be nice), and I need a way to measure the current, I have a multimeter but it wil only go up to 200 mA, I don't want to wait that long so I prefer full amps when I do it, I borrowed a ammeter from school and I kept that for a long time so I don't want to impose on them again to borrow something, especially now that they will be using it soon.


Tell me, were you very successful making chlorate, how much did you make? in how big of batches? any other advice?

I'am an Electrican not a chemist.

well, I fancy myself a physicist before a chemist, not that I am an expert at that either.

 

[Sparkee]

chlorate production

I used a 2 Gallon container, 1600g of NaCL in a saturated solution,8 carbon arc rods that were connected with magnet wire to the cathode,some stainless steel hard ware for an anode. the power supply was one that I picked up at a discount computer store for $10.00. I ran it at 5v and 6 A for 300 Ah keeping the liquid level constant with addition solution. I cut off the bottom of one of the containers and drilled 8 holes around the perimeter and one in the middle. I suspended it from some fiberglass unistrut above the cell. I had the voltage and ammeters from various demo jobs that I had done. If I can locate the pic's I could show you my set up. I was actually quite pleased with the yeild I don't recall the exact figures it was well over 500g. And turned out some great flash powder. My aim was and is for homemade fireworks. (my sons birthday is July 4th.) I have had modest success with that
I too had several tries fail, disentagrating electrodes, power supplies failing,just to name a couple. But, persistance won through! I have since deconstructed my cell as have made enough for my purposes. I will look for my information and would be happy to share it with you if you like. There is nothing like a big BOOM especially when you made it your self.

 

[mrjeffy321]

I have to say, potassium chlorate is indeed very fun to, excuse the word, play with. I have made some pretty cool demonstrations for other people with the meager amounts I have, some of the good ones I video taped and edited on the computer which I hope to put on a website one day soon.
Most recently, I made a "rocket powered car" using a glass jar and chlorate, it didnt work as I expected from the other tests, but I did succeed in moving the car 10 inches before it burst compleately into flames.


Your set up was much more advanced than mine, certainly using more solution and prioducing much more.
But I think I will give it another go, I just need to get a power source, I might have an old trash computer with a working power supply I can for this purpose, I will look into it.
Did you make an extra effor in your cell to control the temperature and pH to get maximum efficency? When you ran it, how big of a problem was the water clouding up and dissolving electrodes?
I would be evry interested in seeing the picture you have of your setup if you can locate it.

 

[mrjeffy321]

Actually, now that I look at the power supply I have, I would have no idea how to use it in my cell. I assume it would involve destroying it in terms of it can never be used in a computer again, but I wouldn't know which wires to use or which have what current through them.

 

[Sparkee]

Power supply

Many apologies for not getting back to you sooner. If you look on your PS the connector that goes to the mother board will have a green wire with a black wire on either side. If you jumper the green with the black to the left of it you should have a fan kick on when you apply the AC to it. Then check the red and black for +5 volts if you have that you should be good to go for a Power supply. At the present time I 'am assemblying my set up so I can re-take some pic's that I cannot find. As to the temp and PH, I used a fish tank heater and was able to maintain a fairly constant 75C.for the PH in the AM I would add 10 or so cc of HCl. (Muratic Acid 30%)It seemed to work at keeping the PH within acceptable levels (7-8??) The Electrodes I purchased from a welding supply store. Around $25.00 for a box of 50. After soaking them for a couple of days in linseed oil. (To help against deteoriation of the Electrode.)Allow them to dry?? I took some Magnet wire (22 awg) and made a couple of wraps around the carbon rods finishing off with some hot glue covering the wraps.( Dont forget to scrape the wire before you wrap it.)This should get you a start. I will get the pic's in the next day or so as I get time.

 

[mrjeffy321]

If you look on your PS the connector that goes to the mother board will have a green wire with a black wire on either side.

I have looked at two, old computers' power supplys and I don't see any green wires, let alone any between any black wires.
I do have the casing and wires of another power supply (the 'guts' are gone though) and I do see the 3 wires you are speaking of there. I will tryu to get a better power supply tomarrow or at my next oportunity.

 

[mrjeffy321]

I have gotten a power supply that looks good.
I don't see any green wire between 2 blacks, but I think it will work anyway because on its sticker, it not only has the voltages and amps supplied, but also the color of the wire to get it from.

Here is what it says:
DC output: 235 W max
+3.3 V 15A (Brown), +5 Vsb 1.0 (Green)
+5 V 22A (Red) , -5 V .5A (White)
+12 V 8A (Yel) , -12 V .8A (Blue)
P.G. Signal (Orange), Ground (Black)
(+3.3 V & 5 V Total output 130 W)


If I look at the PS connector, I see these wires in this order (abbrevaited):
R = red, W = white, Blk = black, Blu = blue, Brn = brown, Y = yellow,
G = green, O = orange

Side 1,
R, R, W, Blk, Blk, Blk, Blu, Blk, Blu, Brn
Side 2,
Brn, Brn, Blk, R, Blk, R, Blk, O, G, Y

Obvioulsy my colors don't match up with yours, so I can't just 'find the green', which wires should I use? I really don't want to screw this power supply up, I was lucky to get it, I could really use your advice since you are an electrician.

another thing, let's say that I want to switch from diferent voltages/current from day to day (for various reasons), would I just use the +12 V wire and then the ground wire for example? or would I need to use the -12 V wire? but then there isn't a wire for -3.3 V.

 

[Sparkee]

I believe that you want the PG signal and it's associated wire Orng and Blk,try to jumper between them. You don't have to cut up the plug just insert the wire and turn it on. If that dosent work you could go ahead with the green and black I don't think you will damage anything as it would have to be on for that to happen(The LV side) I tried to hack an Apple Power supply,never did figure it out so I stripped it of parts. The PS I have I picked up at a used 'puter parts store for $10.00. They had about a dozen or so to chose from. I'm still gathering my set-up, I have used it or parts of it elseware on other projects. Idle hands...I'll get more out ASAP. Hope this helps.

 

[mrjeffy321]

I tested it out, and it looks like it doesn't work. I can't get any voltage through any of the wires. I tried the same thing on another power supply that I know is good and I can get 5 volts acros the correct set of wires (and 5 amps), but I can't use this power supply, I'll try to get another one tomarrow.

You said that you used electrodes, electrodes used for welding.
arent those made out of steel with some type of coating around them that is suppose to flake off? if you used those, wouldn't the water get really dirty and the electrodes would get eaten away, or am I thining of a diferent kind of electrode? this is what I was thinking about, it this the type you used,
http://www.msm.cam.ac.uk/phase-trans/2001/PICF0127.JPG

 

[Sparkee]

Electrodes...

No, the one's in that link are not the correct type. The Electrodes I used are used for carbon-arc welding, appx. 3/8 or 1/2" Dia. 16" Long, they are carbon rods that have a copper foil coating on them. I have heard them called gouging rods. I believe the length is fixed but the Dia. is variable up to 9/16". Any welding supply store would have them. Also the copper coating peels off fairly easy once it gets started. I cut them in half and soaked them in a container of linseed oil for three days. I've heard of some applying vacuum to the container, I didnt and they seemed to work fine. They will erode! I think that I replaced mine at the 1/2 way point. They were looking spindley and ragged. Well good luck on the PS. If I can help let me know. I'm working on a spark gap for a coil I built. Have a good one!

 

[mrjeffy321]

I finnally got a power supply that will work, I went through about 6 different ones before I found one that I could use. it is a different type of power supply, but I am getting a good current out of it, although it does drop drastically when in water.
So now I'll give that a try

 

[Sparkee]

Great! The I(Amps) should change once you get it into a saturated solution of NaCl,And the proper electrodes attached.I'm going to try and attach a pic of what I have gathered together.Well, I have to shrink the file size before I can upload it. Once I figure that out I'll send it along.