Chemistry assistance appreciated

P

Peter La

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Mar 26, 2005
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I need some help on a chemistry "problem".

Ok, this is the situation. I am making some smoke canisters for a paintball/ airsoft group, as well as for another hobby of mine: "combat bushcraft" (don't ask :D ). I have access to "real" chemicals so I am by no means relying on "home made stuff" . I have some experience with Potassium Nitrate so this is what I plan on using, also it is much safer to work with. I also have a sort of "bet" worked out with my science teacher on whether or not it is possible, economical, and safe to manufacture Potassium Chlorate using commonly available chemicals. Yes, yes, I know the hazards associated with Potassium Chlorate. I have worked with a small amount and I am confident in my ability to handle it safely. Besides, it is not that dangerous anyway. I am asking here because I know a few forumites are chemists and have knowledge in this area.

The two reactants are Potassium Chloride/ KCl (Water softener salt) and Calcium Hypochlorite/ Ca(ClO)2 (HTH pool Chlorine from Canadian Tire). Purity does not matter, I worked that part out already.

I have read this procedure from a number of sorces, some of which may contain errors so more research is necessary.

The idea is:

Calcium Hypochlorite + Potassium Chloride --> Potassium Chlorate + Calcium Chloride

Ca(ClO)2 + KCl --> KCLO3 + CaCl2

With correct (I hope) stoichiometry:

6Ca(CLO)2 + 4KCl --> 4KCLO3 + 6CaCl2

Using the molar masses:

KCl: 75 grams/ mole
KClO3: 123 grams/ mole
Calcium Hypochlorite: 75 grams/ mole
Calcium Chloride: 111 grams/ mole

The reaction would be (I hope):

450 grams of Calcium Hypochlorite and 300 grams of Potassium Chloride react to form 492 grams of Potassium Chlorate and 666 grams of Calcium Chloride.

Now, the procedure:

1. Add 450 grams of Calcium Hypochlorite to 300 grams of Potassium Chloride.
2. Dissolve this in enough boiling water to keep the two reactants in solutuion.
3. Bring the water to a boil, making sure that everything is dissolved.
4. Allow the water to cool.
5. At 20 Degrees C, the solubility of Potassium Chlorate is only 7 grams in 100 ml so the product should come out of solution. This crystals can then be collected.
6. Calcium Chloride is very soluble at 20 Degrees C (75 grams in 100 ml) so most of it should stay in solution.

The reason I am thinking of doing this (as opposed to using Potassium Nitrate) is that I want to see if it is possible. I do not plan on using Potassium Chlorate for anything, I may even destroy the products after the reaction. Basically, I am doing this to see if it is possible.

I would very much appreciate some help that would clarify if my total theoretical yield would indeed be 492 grams. I know I will loose some through filtering etc., but this is just for "on paper" right now. I have not done this reaction yet since I am still looking for information.

Please, do not think I am some pipe bomb wielding maniac. This is the farthest thing from the truth. I am simply someone who enjoys the more "practical" side of chemistry.

Thanks for any help or guidance you can give.
 
Other than phase changes and diagrams, I am pretty rusty at chem, but shouldn't this:

6Ca(CLO)2 + KCl --> 4KCLO3 + 6CaCl2

Really be?

6[Ca(CLO)2] + 4(KCl) --> 4(KCLO3) + 6(CaCl2)

Parentheses and brackets added for clarity.
 
For some reason, I seem to recall that another chemical should be added to precipitate chlorate out.

Then another reaction to separate.

I'll look around in my books. (I don't have that many).
 
Been many years since I played with that stuff, but if I remember correctly, you may have to fiddle with the pH to help drive the reaction or produce a less soluble calcium salt. I do remember that a mixture of calcium hypochlorite and sugar burns quite well though ^-^
 
ARRRGGGGGHHHHHHH! You just made my brain hurt and gave me bad flashbacks to highschool chemistry. (I'm surprised I could remember that far back!)
 
I tried this out and did not have any success. In fact, the solution bubbled over and started smelling of Chlorine. No product.

yuzuha said:
Been many years since I played with that stuff, but if I remember correctly, you may have to fiddle with the pH to help drive the reaction or produce a less soluble calcium salt. I do remember that a mixture of calcium hypochlorite and sugar burns quite well though ^-^
Click to expand...


Yes, but it smells of Chlorine. KNO3 and sugar works very well and smells very good. :thumbup:

I am probably going to give up on this since I can just buy pretty much anything I need. Homemade chemicals are a pain to do, dangerous, and they often do not work.
 
Sorry I'm late, had to think about it a bit (been awhile since i did inorganic). First I think the water softner salt might be NaCl. Secondly I'm not sure the reaction is going to want to go that way; halogens in the higher oxidation states want to go to lower oxidation states. You usually have to use a stronger oxidizing agent to get ClO3. Also if you ignore the cations what you are trying to do is 3(OCl) + Cl-----> ClO3 + 3(Cl) (all are anions); this reduces to 3(OCl)-------> ClO3 + 2(Cl) (all are anions). I'm not sure how they are teacing re-dox reactions now; I know they were doing it differently when I was a senior in college than when I learned them in high school. I think if you were to check the potentials involved with the half reactions you were trying to have take place you would find they wouldn't go (if that makes sense). I think it would work if you had tried for bromate BrO3.
Anthony Lasome (chemist who deals with organic compounds and how they fragment in a mass spectrometer now)
 
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