Making Hydrochloric acid + Halogen Chemistry.

[YT2095]

are you doing the propper 70/30 mix with the Alu?

 

also, you are in Extreme danger doing this with your current Batch, the copper ions in there will Certainly!!!! make a very unpredictable mix!

[[w00t]]

i didnt test with acid, dont have it in the house at the moment.

ill do another batch and leave it running longer.

 

and yer i tried a few diffrent mixes, 70/30 and 50/50 . no diff

[[w00t]]

I made 2 grams of KClO3, burns with a nice purple flame, but doesnt do anything with Al, probably because its atomised. could it be turned in to flake using a mortar and pestle?

 

Also i was reading back, my resistors were only 30 cents each, 5 for $1.50 (AUD) i dunno why you get it so expensive.

 

 

edit: Would mixing KNO3 into the soln of NaClO3 yeild potassium chlorate? since kinda nearly all stores in my area discontinued selling KCl

 

 

edit2: i stuck a heatsink on the 5 resistors cuz they get pretty hot (hand burning hot)

[YT2095]

Never mix Chlorates and Nitrates, that`s simply asking for trouble.

 

good call with the heatsink though

[woelen]

@YT: Why not mix chlorates and nitrates? But are oxidizers and as far as I know they do not react at all. to my opinion it is perfectly OK to add a concentrated hot solution of KNO3 to a concentrated hot solution with NaClO3. The KClO3 then will settle as nice crystals on cooling down.

 

@[w00t]: Did you really buy 5 W rated power resistors? What size do your resistors have? Mine have a length of appr. 4 cm and a width of appr. 6 mm. They are the off-white ceramic things, rated for 5 W power consumption.

However, if your resistors only become "hand-burning hot" then I would not worry too much. My resistors sometimes become VERY hot. But ceramic resistors can stand very high temperatures. Temps of 125 C are no problem at all and such a temp is not "hand-burning hot", but very hot, causing immediate blistering of your skin. Attaching a heat-sink to the resistors, however, is perfectly fine and if it makes you feel more comfortable, I would say, do so.

 

If you have a few crystals of potassium dichromate at hand (for 100 grams of salt, 0.1 grams of K2Cr2O7 will do perfectly well), then you can increase the efficiency of your cell considerably. What happens is that chlorate ion is back-reduced at the cathode, when the concentration rises. What happens over there is the following:

 

ClO3(-) + 6e + 6H2O --> Cl(-) + 6OH(-)

 

besides the formation of hydroxgen. So, part of the chlorate present in solution is destroyed again at the cathode. This effect can almost be brought to an halt with just a tiny amount of dichromate present in the solution.

 

Ask at your school if you may have 1 gram of K2Cr2O7. With that you can easily prepare 1 kilo of salt-solution. Beware, however, K2Cr2O7 is very poisonous and it is a probable carcinogen.

[YT2095]

nitrates and chlorates together have rather unstable breakdown products, esp in the presence of metal.

making it as bad if not worse than any Copper ions could ever be for unpredictability.

[woelen]

Conclusion: Chlorates are quite bad for pyro-applications anyway. Who can guarantee decent purity with chlorates, especially home-brew stuff? That is why [w00t] should be VERY careful with his home-brew chlorate anyways, regardless of what chemicals are used to make it.

 

Chlorate is, however, a fun chemical to play with, in small demonstrations and redox experiments, for more serious work it is too dangerous. I myself hardly use any chlorate at all (although I have almost 1 pound of this stuff around). I do not do real pyro-stuff (not allowed in The Netherlands) and for aqueous redox chemistry chlorate is not the best oxidizer. It does not react cleanly, a lot of side reactions occur, when chlorate is used as oxidizer (formation of chlorine, chlorine oxide(s) besides the main reaction, where chloride is formed). This makes redox experiments, where one wants precise control over the reaction products almost impossible.

[[w00t]]

(not allowed in The Netherlands)

 

well atleast you guys have weed legalised lol

[[w00t]]

@woelen

 

yer it's 5w 22ohm. its a small white rectangle, i dont have a ruler handy so dont know the measurements.

 

Could you use something else other than potassium dichromate?

[woelen]

Dichromates are not so difficult to make in small quantities, and besides that, you do not need to isolate the dichromates.

 

You have KNO3? And you have NaOH? If so, go to a ceramics supplier and buy some Cr2O3 (green chromium oxide). A few grams is sufficient. Melt a few spatulas of NaOH in a small inox spoon, add a spatula of KNO3, which also melts into the NaOH and then add some Cr2O3. The liquid will turn yellow. That is due to formation of chromate. Only use very small quantities, because working with the molten NaOH is quite dangerous. Let the yellow stuff solidify and add this to a small quantity of water. You'll get a yellow solution, probably with a lot of insoluble crap. Let settle and then decant the clear yellow liquid. This clear yellow liquid contains chromate (and still traces of nitrate).

 

This yellow solution should be acidified with hydrochoric acid carefully, until the solution turns from yellow to orange yellow (not further, its pH should remain 7 or above). If the liquid becomes bright orange, then too much acid is added. Then ou need to add some NaOH again. This almost neutral liquid can be added to water, in which you dissolve your salt. One spatula full of Cr2O3 will give sufficient chromate for several 100's of grams of salt.

 

Another way of making chromate is as follows:

Get yourself some chrome alum (photo chemical suppliers, some drugstores also sell this, it is a totally non-suspect chemical, used in hardening fixers in photography), dissolve a spatula of this in water. Add a solution of NaOH, until the precipitate, which first forms, redissolves again and you get a clear green solution. Next, add some 3 to 5% H2O2 and carefully heat the liquid to 60 .. 70 C. The color will change from deep green to lemon-yellow (if too much chrome alum or H2O2 is used, the liquid may become somewhat brown/yellow, that does not really matter). Once the liquid is yellow, boil vigorously for some time to get rid of the last traces of H2O2 and then carefully add some hydrochloric acid to make it orange/yellow again (chromate is converted to dichromate). Then dilute with water and dissolve the salt into that liquid.

 

Beware: chromate and dichromate contain hexavalent chromium and compunds, containing that probably are carcinogens, so be very careful not to be exposed to these compounds.

[[w00t]]

Hmm i made a warm soln of kno3 (30grams) and mixed it my hot soln of NaClO3 (initally used 60g of table salt) and i mixed them together, i stuck it in a fridge to cool it a bit, then i filtered the crystals out. now the crystals look like kno3 and not kclo3, if there actually any different between them, lets jsut say it didnt look like my previous kclo3 ill wait till its dry to see how it burns

[woelen]

Crystals of KNO3 are needle-like and crystals of KClO3 are like little scales. Yes, they are quite different.

[[w00t]]

here, i mixed 4parts kclo3 with 1 part sugar + 1 part charcoal (i think)

 

anyway heres the video of burn ~0.2g

 

http://media.putfile.com/02g-kcl3-c-su-4-1-1

 

 

here it is again with kclo3 + charcoal only (wet mixed with dextrin then dried and repowderised) it went slow could be my charcoal, its to damn fine, wouldnt mix properly so i had to wet mix it

 

around ~0.2g aswell 70/30 ratio

 

http://media.putfile.com/02g-kcl3-c-7-3

 

edit- the first one burnt much faster when sulfur was added (yes i know the chlorate + sulfur rule )

[woelen]

[w00t], well done job. That looks quite good.

 

I want to give you one suggestion: Do not light such mixes with a short match. The mixes you have here are burning with a smooth flame, but I have had mixes, which reacted very unpredictably, spraying all kinds of moltens salts around. Last year, I burnt my fingers from just 50 mg of red P/KClO3 mix, "lighted" by mixing it with a little wooden stick. The stick had a length of approximately 20 cm, but that was not sufficient to protect my hand and fingers from being burnt. I must not think of having 200 mg of this mix, lighted with a short match.

 

You can buy so-called barbeque-lighting matches (at least over here, I don't know the situation in Australia), try to find those. It is much safer.

[[w00t]]

it burns so well when its rolled in to a star shape, i light up a round ball just on the ground with a fuse and it goes in to the air (like a metre) and spins.

 

anyway, could these be used as rocket fuel or there would be a CATO

[woelen]

For rocket fuel I would suggest you to stay to KNO3. A lot more stable and well burning at an acceptable rate. For rocketry you don't want too high burning rates. Of course, you could add a payload with some nice effect, where you could use some of your home-made KClO3, but as YT and I warned before, keep in mind that KClO3 is a notoriously sensitive and unstable chemical, which already has cost many persons limbs or more. So, feel free to experiment, but always be prepared that something can go wrong with KClO3.

I myself use the KClO3 I have only for fun experiments, with some flashing, high-speed buring powders and so on, but to my opinion it is not suitable for real pyrotechnics, unless you have a lot of experience of knowledge.

 

If you really want more about this subject, then I suggest you to read the following very interesting forums, devoted to pyro and rocketry. I did not register in them, but I regularly read them with pleasure.

 

General pyrotechnics: http://groups.google.com/group/rec.pyrotechnics

Rocketry: http://www.ukrocketry.co.uk/forum/index.php?act=idx

 

Interesting reads....

[[w00t]]

Is it normal for the electrolysis cell to soap/foam up, like a lot of bubbles everywhere in the mix

[woelen]

Are your graphite electrodes treated with some linseed oil? This is a good thing, because it makes them less vulnerable to corrosion, but it also adds more crap into the solution, most notably, forming kind of foam on the surface of the solution. This behavior can be reduced somewhat by diluting the solution a litte. E.g. add 1 part of water to 4 parts of the solution. I also read about adding a drop of a detergent to the solution. This reduces surface tension and may reduce foaming. Your mileage may vary though.

[YT2095]

"Bubble rafts" are common in such cells, but Foam?

 

as for the detergent idea, I`m not 100% sure of that either, I think a few drops of Alcohol may serve you just as well for surface tension.

the reasoning behind this is that the free OH part should saponify any oils (linseed) to form a Soap (detergent) anyway, and so I can`t see how adding More would assist in anyway.

 

IMO, adding a detergent could only serve to Amplify this problem.

[woelen]

YT, that is why I wrote that your mileage may vary. But, it is sometimes true that adding a detergent may reduce foaming, due to interaction with other foaming agents.

 

I would not add alcohol. That reacts with hypochlorite and chlorine and reduces the cell efficiency to 0. As long as alcohol is present, no chlorate is formed at all! Before the hypochlorite can disproportionate to chorate and chloride, the alcohol has reacted with it already.

The reaction, which occurs is the so-called haloform reaction.

[YT2095]

I did once (whilst drunk and a little younger), give my chlorate cell a "drink" also (for being so good to me (don`t ask)).

it had no deletarious effect upon it, certainly in anyway that was Noticable in yeild, and no odd halokane smells after either (it was only Vodka though).

 

I`m still quite certain that any Linseed in the graphite would saponify and become its Own detergent anyway, and more stearate molecules could onlyadd to this.

Maybe that`s the actual Cause of the "Foam"?

[[w00t]]

I think it had something to do with it being warm, cuz after a while it went back normal (i dont treat my crap with oil )

 

when i attached the second set of resistors. it went much hotter then just using one set, by hot i mean more then just hand burning hot. i reckon a minute on a paper will light it on fire. (also i could see a line of gas going up a metre above the beaker)

 

so i put another heatsink and stuck a fan over it

 

edit- if i stuck 10 in parallel, thats like 2.2ohms of resistance, so that would be ~5.45a if what i learnt in physics is correct... would that setup work? wouldnt 5a take like 2-3x quicker to complete its job?

[woelen]

No, the physics and chemistry both are not correct. With 10 resistors indeed you get appr. 2.2 Ohm effective resistance, but your current will be at mose somewhere between 3 and 4 A. This is due to the voltage drop across the cell. The cell also takes 4 to 5 volts, and the remaining voltage will be across the resistors. Look at the page, which I wrote some time ago, this explains why the cell voltage is not 0.

 

Increasing the current by a certain factor does not increase the speed at which chlorate is formed by the same factor. You even can make the cell, such that its efficiency goes down a lot, while more currrent is sent through it. It all has to do with current density on the electrodes. As I wrote before, keep the current density below 100 mA per cm². If you really want to draw more current with your second set of resistors, then make up for a second cell, and connect that to the second set of resistors, and connect both cells to the same PSU (that certainly will power both cells without problems).

 

What you now are doing is producing lots of hydrogen and oxygen, producing lots of heat and only making relatively low amounts of chlorate. So, make another cell and do not rise the current too much though a single cell.

[[w00t]]

i found some nichrome wires lying around, would it work as a cathode material? and circle it around the carbon anode electrode? or would it heat up to much causing to much evaporation?

 

i know nichrome is expensive and it can be used for better things...

[DougBrummell]

tell me if I am wrong, but I was under the impression that pH wasn't actually pH, but rather ro (greek symbol) H, and it is the negative log of the H+ concentration, oppositely there is pOH. . . it just seems as though the ro evolved into a p to most people/institutions.