Sciencemadness Discussion Board - A word on Chlorine dioxide

A word on Chlorine dioxide

chloric1 - 9-10-2003 at 08:54

Ok I have read numerous post on chlorates, perchlorates and the free acids. I was especially intrigued by use of ClO2 with hot water for HClO4 . I believe this could be done effectively and safely considering a few safety measures. First the MSDS for Chlorine Dioxide stated you do NOT want to use more than 100mmHg partial pressure. What this means that you should use an inert carrier such as filtered air or CO2. Secondly you do not want ClO2 to contact organics.

I have taken an interest in this gas lately as I do have 2 Kg of KClO3 to mess with. I have only messed with test tube quantities because I have neigbors quite close to me.

But the methods I have used so far are safe reliable and productive. First take potassium chlorate powder and mix this with approximate equal oxalic acid and add sufficient battery acid(H2SO4) to cover becuase this will generate your chloric acid in solution. next prepare a hot water bath of at least 75 C. then immerse your concotion(in glass tube) into water bath and the gas will be given off along with CO2. you could buble this into water to make acids or into ice cold BaOH H2O2 mix to make Barium chlorite. Since KClO3 is of limited solubility only the chlorate reacting will dissolve until the decomp of the oxalic aicd is complete. The gas is MUCH heavier than air and tend to remain in the flask?tube so you should bubble CO2 gently in to force this gas into the second reaction vessel. The idea of the water bath is gentle controllable heat. Good luck and be careful and remoive any flammable liquids and easily oxidizables before you proceed!

KABOOOM(pyrojustforfun) - 10-10-2003 at 20:03

<blockquote>quote:<hr>I was especially intrigued by use of ClO2 with hot water for HClO4<hr></blockquote>u mean making HClO4 using ClO2? sounds odd, ClO2 hasn't got enough O to be even anhydride of chloric acid. plz give more info on it. ever thoght of mixing sols of dihydrazinium sulfate and barium chlorite? if ClO2- doesn't react with hydrazine N2H5ClO2 will form. a incredibly unstable and sensitive and damn powerful explosive with perfect OB! N2H5ClO2 <s>   ></s> N2 + 2H2O + HCl

chloric1 - 11-10-2003 at 08:11

KABOOM. Yes I suppose, in theory, you could react hydrazine sulfate with barium chlorite to make hydrazine chlorite but I have never heard fo its existence and I think any attempt at its developement would result in detonation. As for your question about perchloric acid from ClO2 it is a complex process. Firstly ClO2 reacts with water to form chloric AND chlorous acid much like NO2 makes nitric AND nitrous acids in dilute solutions. This is because the ClO2 oxidizes itself! How is that for oxidizing power!?? Second chloric acid solution when concentrated by boiling decomposes to HClO4 an chlorine gas. The chlorine is a result of the reduced portion of the chloric acid. So, as you may guess, the yield is poor but if you have large quanties of potassium or sodium chlorate, battery acid, and oxalic acid; you could make a considerable quanitity of perchloric acid. Personally I still have about 1500ml of 70% perchloric acid but I amy perform this experiment just for academic curiosity.

[Edited on 10/11/2003 by chloric1]

yyeeeeaah

KABOOOM(pyrojustforfun) - 11-10-2003 at 20:12

I can finally have some perchloric acid I don't care for low yield. it's awhile i've been seeking for this baby.
is it what happens?
14ClO2 + 4H2O <s>   ></s> 8HClO4 + 3Cl2

[Edited on 12-10-2003 by KABOOOM(pyrojustforfun)]

blip - 12-10-2003 at 07:47

This is what's really going on, if I'm not mistaken:
2ClO2 + H2O <s>  ></s> HClO2 + HClO3
HClO3 + HClO2 <s>  ></s> HClO4 + HOCl
4HOCl <s>  ></s> HClO4 + 3HCl
I don't see where chlorine gas would evolve, though.

Btw PJFF, last time I tried doing a strike through a greater-than symbol, it went through and looked quite bad. Apparently something has changed.

chloric1 - 12-10-2003 at 09:35

Quote:

I don't see where chlorine gas would evolve, though.

Realise that in ClO2 the chlorine has an oxidation number of 4 and when this forms chlorous and chloric acids, part of the chlorines are oxiidized to +5 while the others are reduced to +3.

Likewise, a simular thing happens when you heat chloric acid to decomposition. remember that if you melt KClO3 it autoxidizes into KClO4 and KCl now the same is true of the free acids. Hence the evolution of chlorine gas. But, and I mean but, you will have chlorine in various concentrations in this aqueis concoction. So it could be that the chlorine is oxized as it is evolved but I doubt it.

blip - 12-10-2003 at 09:58

Oh, like one of the oxidizing acids oxidizes HCl into Cl2? I didn't think of that, sorry.

KABOOOM(pyrojustforfun) - 12-10-2003 at 21:24

blip let's disscuss HTML tags using U2Us or make a topic on forum matters. it doesn't have any thing to do with chlorine dioxide(as far as I know

). I also misunderstood u by greater-than symbol

chloric1 please tell us your source(s) of info.
I think when boiling a chlorate salt adding a dilute solution of oxalic acid with very slow rate (drop by drop) you get chloride and perchlorate at the end. if this works it'll be quite safer and easier than getting chlorats to melt.

Marvin - 14-10-2003 at 07:46

Ive heard of the oxalic method before, but I havnt heard of using dilute sulphuric acid to help push it along, interesting. Should result in a mixture of 2 volumes CO2 to 1 volume ClO2. A lot safer and on the right side of the 300 torr pop/bang threshold.

Needs to be mentioned that this is dilute sulphuric acid, as concentrated sulphuric acid and chlorates is a very bad thing.

Hydrazine chlorite will almost certainly just evolve nitrogen gas on formation as the solutions mix.

I have a big problem with the perchloric acid idea. To start with just assuming that a solution of the gas in water will be a solution of both acids isnt right. Like ammonia which in solution is mostly NH3 and is only a tiny part NH4OH, most of the chlorine dioxide will just be as chlorine dioxide. Given the method of preparation I wouldnt expect the solubility in water to exceed a few grams a litre, and when you heat it, Id expect it to leave if it can. Given you start with a solution thats only about 0.3% and you enter into a process you think will be low yeilding, I wouldnt hope much for a result. Chloric acid itself seems to like to decompose by producing oxygen, not the disproportionation we were expecting and furthur wrecking the yeild.

I would think that carefully fusing the pure salt could work. Or a bit safer, oxidising it to perchlorate with silver(I) catalysed persulphate in aq solution.

chloric1 - 15-10-2003 at 19:01

I think when boiling a chlorate salt adding a dilute solution of oxalic acid with very slow rate (drop by drop) you get chloride and perchlorate at the end.

Ok I am sorry, I must have been unclear in my original message. The information is based on my experiments. As I have said I have only used test quantities. But what I did was I took solid KClO3 and solid Oxalic acid then I added sufficient battery acid to cover witha little extra. I heated this in a water bath to drive off chlorine dioxide. What i was suggesting was dissolving this gas into ICE cold water and then heating this slowy to generate HClO4. But if I had not said so before I have only generated the gas and have not performed the autooxidation.

KABOOOM(pyrojustforfun) - 17-10-2003 at 19:41

Marvin did you mean ClO2 is in equilibrium with the acids?

chloric1 I still don't know whether you theorised the formation of HClO4 via ClO2 or you got the info from a scientific source?

Edit: I hadn't read the perchloric acid preparation topic. it's been disscused there.

[Edited on 19-10-2003 by KABOOOM(pyrojustforfun)]

Chlorine dioxide

chloric1 - 18-10-2003 at 19:45

Ok THe HClO4 from ClO2 and hot water is from more than 1 scientific source but it has been many years so which one I do not recall. My experiments are merely pointed out that ClO2 from KClO3 and oxalic/sulfuric acid solution proceeded smoothly because KClO3 has limited solubility. I was just suggesting some output uses for the gas. It is rather interesting in itself and I like the smell

.

But if you Whiff it do it indirectly because it can pack a wallop and put you in the hospital!!