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LawnMaster1
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post your favorite chemical reactions
hello all, I'm new to this forum, and have a huge interest in conducting some chemical experiments at home this christmas during my break from
college.
I would greatly appreciate it if you posted your favorite chemical reactions that give really cool reactions; making sure to give both the chemical
name (aka potassium nitrate) and common name if there is one (aka saltpeter) for the reactants.
Please be sure to give any advice on precautions or imporvements that can make the experiments safer and/or more enjoyable.
I hope to become a part of this forum and learn the scientific terms ya'll use  .
This is also a great way for this forum to compile all the good experiments it has done, post pictures, and discuss them.
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I myself have thoroughly enjoyed trying to make rocket engines, by mixing potassium nitrate with sugar and boiling it down untill it is a pla-do like
substance. I then shape it into the desired shape and light it off to hiss and large puff of smoke.
KNO3 + C12H22O11
I have also tried making thermite using homemade aluminum dust and rust, however haven't succeeded in this one yet. (any suggestions?)
[Edited on 14-12-2006 by LawnMaster1]
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Maya
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My favorite rxns are anything that involves Palladium ( 0 ) Tetrakistriphenylphosphine.
Just Kiddin', actually as a young student of chemistry some of my most enjoyable experiments were iodide salt and ammonia to make nitrogen tri-iodide
and also white phosphorus and sodium hydroxide solution to make smoke rings. Now I am more grown up and don't look for such instant gratification
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Greenhorn82
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I used to enjoy making nitroglycerin and nitrocellulose, but I got bored of it. Too much work, and not a good way to detonate it. Now I'm having fun
with thermite.
You can get the ingredients and pre-mixed thermite easily from eBay. I recommend using black iron oxide rather than red, because it burns much more
vigorously. It's hard to find good aluminum powder unless the store specifically sells it - I don't believe in buying an etch-a-sketch or grinding up
aluminum powder. You won't get a good reaction with it, and it's too much work. Just get it from eBay or a science shop (eBay is probably cheaper.)
Iron oxide, on the other hand, is easy to make. Buy some super-fine steel wool, stack the biscuits into bales and ignite it. It should glow for a
good 15 minutes. When it cools, crush it into powder. The stuff that doesn't crush (mostly on the outside of the bale) is not fully oxidized, so
don't try to use that.
Or you can get chromium oxide and make thermite with that. It's also very fun. I'm thinking of trying some other metal oxides sometime.
I also just made some "rose" metal, which is a mixture of bismuth, lead and tin. It's not a chemical reaction or anything, but it's fun to play with.
It's an alloy that you can, if you're careful, stick your finger in when liquid, since it melts at below the boiling point of water.
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DeAdFX
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Fun reactions....
BZ oscillating reaction
Acid/Base neutralization
Double displacement reactions
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cool_arrow
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A Grignard is a very interesting reaction. It may perhaps stand out in my mind in that it was the one time I was unable to control things and my
reflux condenser spewed partially reacted gunk all over the lab ceiling. Learned a good lesson in scaling-up of reactions and had good success with
subsequent reactions.
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chochu3
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http://www.cci.ethz.ch/index.html has some nice expirements.
\"Abiding in the midst of ignorance, thinking themselves wise and learned, fools go aimlessly hither and thither, like blind led by the blind.\" -
Katha Upanishad
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woelen
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I have some nice experiments on my website. Most members probably know them already, but I'll repeat them here for the newcomers:
http://woelen.scheikunde.net/science/chem/exps/index.html
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YT2095
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I have so many that I enjoy it`s hard to pick a favorite, but 3 test tubes with dilute nitric acid in each 20-30%, and the Cobalt, Nickel and Copper
dropped into each tube.
a short while later you get perfect Red, Green and Blue colors produced.
it looks nicer done side by side than individualy.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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Elawr
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What comes to mind right now is KI in solution to which a little Pb(NO3)2 is added. PbI2 falls out as a wonderful yellow-orange precipitate - swirling
around like a snow globe full of golden spangles!
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Maya
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What comes to mind right now is KI in solution to which a little Pb(NO3)2 is added. PbI2 falls out as a wonderful yellow-orange precipitate - swirling
around like a snow globe full of golden spangles!
Don't forget the other half of this wonderful expt,,,, When you get that nice orange precipitate and dry it then heat it strongly it turns into a
beautiful purple cloud of iodine crytals and a puddle of melted lead!!!  
[Edited on 15-12-2006 by Maya]
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Elawr
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Wow!... I've never tried that before. I'll definitely have to do that - good excuse to make up some more PbI2.
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Dr. Beaker
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as a high school student I made Pb, Cu soaps by mixing CuCl2 or Pb(NO3)2 with soap solution, and disolved it in parafin. I made a candle from it and
the Cu candel burned with a beutifull green color + red Cu metal acumelated on the roap-like cloth that carry the parafine(don't know the word for it)
the Pb candel was interesting in that it produced shining dropletes of Pb metal that "digged" inside the parafin because of the heat. hwever, because
of the poisoness of lead I would do it in a well ventilated place.
[Edited on 15-12-2006 by Dr. Beaker]
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The_Davster
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That sounds cool Dr. Beaker. I will have to try that. The word you were thinking of was 'wick'. Strontium salts could be interesting as well.
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UnintentionalChaos
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About what ratio of copper soap to paraffin will get a good, strong flame color? I happen to be in the middle of making CuCl2 for various reasons and
this adds another one to the list. Great idea!
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Dr. Beaker
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It was 15 years ago so I don't remember the exact procedure (I didn't took notes of the experiment...).
I just remember that when I used about 1:1 weight ratio the candle didn't burned well because Cu particles clogged the wick.
obviously, you need a "real" soap for this (i.e fatty acid alkaly salt) and not detergent soap
P.S no.1: now that I think of it it can be a nice way to make alloys of metals without using meltpots etc. since the metal ion is reduced in the flame
by C/CO/H2 and is in gasous state at this stage.
P.S no. 2: the metal soaps can be thermolized to make the metal carbonate and a ketone:
(RCOO)2M ----> M(CO3)+ R2CO
or the oxide if the decomposition temp of the carbonate is lower then thermolysis temp.
[Edited on 16-12-2006 by Dr. Beaker]
[Edited on 16-12-2006 by Dr. Beaker]
[Edited on 16-12-2006 by Dr. Beaker]
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woelen
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| Quote: | | Don't forget the other half of this wonderful expt,,,, When you get that nice orange precipitate and dry it then heat it strongly it turns into a
beautiful purple cloud of iodine crytals and a puddle of melted lead!!! |
I just did the experiment, and indeed, it is a very nice experiment.
If the PbI2 is not heated strongly, then it changes color reversibly. At room temperature it is yellow, when hot (70 degrees or so), then it is red.
When allowed to cool down, it becomes yellow again. Very nice. PbI2 can almost be made black, before it decomposes.
On much stronger heating, it looses I2 and a thick purple vapor is formed, which forms nice crystals at cooler places.
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Jdurg
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I'm quite fond of the bromine + aluminum metal reaction. Though I must say that you need INCREDIBLY good ventilation for this and a way to contain
the reaction products as the bromine/aluminum mix reacts very violently and bromine can be nasty on your skin or in your lungs.
\"A real fart is beefy, has a density greater than or equal to the air surrounding it, consists of the unmistakable scent of broccoli, and usually
requires wiping afterwards.\"
http://maddox.xmission.com. |
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UnintentionalChaos
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I finally got around to making some copper soaps. Since I have been cooking since I was 10 and didn't get into chemistry until somewhat recently, I
apologize for my constant use of cooking terms. It never occured to me, but the soapmaking (which I do as a hobby anyway) is a very interesting
reaction. For those of you who are artsy as well as chemically inclined, homemade soaps are a dirt cheap holiday gift that nobody sees coming (and
nobody has complained about at all yet ). Here's how I proceeded in making the
copper soaps.
200grams of canola oil (rapeseed for those of you in europe) were placed in a large beaker. In another beaker, 70ml of water were placed. Based on
saponification values, 28grams (slight excess) of sodium hydroxide were added to the water (NOT the other way around...same bad idea as adding water
to acid) and stirred until it fully dissolved. Once the hydroxide solution cools to about 50C, heat the oil to the same temperature. The hydroxide
solution cools MUCH slower than the oil can be heated. This mixture was agitated massively using an immersion blender for a few minutes (stirring is
no good unless you have a long time to stand there and stir rapidly...stirbar is useless) until the "soap" thickens. This is called tracing because
drops of soap will not sink immediately into the rest of the mix leaving a "trace" For this application you can go until it resembles pudding though
for hand soap, this is a really bad idea. This was placed in a water bath and maintained at about 93C for 4 hours, adding water periodically when it
appeared to be getting silghtly dry). The heat accelerates the saponification reaction and can bring it to completion in a few hours whereas the
standard "cold process" soapmaking takes 2-4 weeks to completely react. The soap was then mixed with around 5 times its volume in water and blended
with the stick blender into a thick paste. 90grams CuSO4*5H2O were dissolved in the minimum amount of water possible and this was stirred into the
soap paste. Immediately, the soap coagulates into globs of blue-green, water insoluble, copper soaps. This has an awful habit of sticking to
everything, so unless you have a lot of heptane, benzene, or heptane to waste cleaning everything, plan to throw out the containers you use from here
on. Plastic wrap is very helpful. Since the oil used was canola, the majority of this soap is a mix of copper oleate, copper linoleate, and copper
linolenate. Collect the soap (gloves! this stuff is so much worse to get on your hands than pine sap) in a big glob and place it on plastic wrap. In
order to remove the sodium sulfate and glycerin contamination in the soap, add it to several times its volume in water in a large beaker. Heat the
water until the soap melts (definetly below the boiling point of water) and the water clouds. Mix the soap around to try to expose as much of it as
possible to water in order to wash out the soluble sulfate and glycerin. The soap does not like to stick to glass when liquid in the presence of any
thin films of water so you're in luck at this stage. It also does not like to stick when chilled to freezer temperatures (which is where I'm storing
it) because it becomes hard and rubbery (but still easily breakable). Pour the melted soap into an ice bath and wait for a decent layer of solid to
form so it can be removed from the bath and freeze it. This soap still has significant water contamination, so dry by any method of your choosing (If
I had a vacuum pump, that would be my choice, but i heated it in the oven at 90C for many hours. A very interesting and very messy experiment up to
this point, though I found it completely impractical for making candles. I started with a 1:16 ratio of soap to wax, but no color was observed. By
3:16 ratio, the wax no longer hardened correctly when cooled, yet still no color. I have temporarily put the experiment on hold with the mix at 1:4
because it solidifies into a very thick, rapidly melting paste when cool which is impractical for anything more than a demonstration. (perhaps a jar
candle could still be plasible). It shows some color, but is still noticably yellow from the wick burning. I will continue to experiment with it in
the future, but have called it off for the moment. I froze the whole block of wax in the freezer, which makes it manageably hard.
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UnintentionalChaos
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Holy shit, can I talk. Anyway, for those of you interested in making your own soap for actual home use, I recommend this site. http://www.thesage.com/calcs/lyecalc2.php It does the simple calculations with saponification values for you. (Saponification values being how
much KOH it takes to fully saponify a kg of a given oil, a derivative of molar ratios and the types of fatty acids in a given oil). Canola oil is
actually a bad choice. You can use it for 1/4 of a soap batch's fat without ill effect, but more will make a soap that quickly goes rancid and stays
fairly soft. KOH also makes a soft soap, so NaOH is preferred. Coconut oil, Palm oil, and palm kernel oil all make for a hard bar that lathers
extremely well. Olive Oil also makes for a hard bar. Best of all is to include a little castor oil (look for laxatives in your local pharmacy) for its
moisturizing and foaming properties. My standard mix is a combination of about a third coconut, a quarter olive, a quarter canola, and a sixth castor.
Do not work in batches smaller than a pound of fats because it will cool too rapidly and have issues reacting properly. Before you do any of that, you
need a mold. A good one is an old pringle can for round soaps or a shoebox (though these fit batches of about 3 pounds of oils better) In the case of
the pringle can, lubricate the inside with a little extra oil to keep the soap from sticking. You could use petroleum jelly, since that can not be
saponified, though regular oils are just fine. For a shoebox, drape a trashbag or plastic wrap with a little oil on it into the box. Mix the
calculated amount of lye (I like the measurement for 7% extra fat) with the maximum amount of water the calculator reccomends and then heat the oils.
Mix them together (This big a batch can be whisked for about 15 minutes or the blender can do the same job in a minute) until trace. You can add a
tablespoon or two of extra glycerin to make it more moisturizing. An important addition is a teaspoon of vitamin E acetate (tocepheryl acetate,
available as a beauty product) to keep extra oils from going rancid and also to make it even more moisturizing. Some soaps (most) get an oily odor
when stored, so essential oils are usually added. A tablespoon per pound of oil is usually plenty, though not all essential oils are compatible with
soaps. To avoid doing research for a first batch, pure lavender oil is compatible and cheap. Pour the mix into the prepared mold and insulate with
towels to contain heat. The soap will set, then heat up and liquefy (gel stage) as the saponification continues to occur. This may occur 24 hours
later or within a few hours of pouring. In this reaction, fats are disassembled into fatty acids and glycerol. Glycerol combines with the hydroxide
ions and becomes glycerin. The fatty acids combine with the sodium and become soap. Since these soaps are one fatty acid and one metal ion, they have
a nonpolar end and a polar end, making them very useful at removing oily dirt when washing hands. A copper soap should have two fatty acids to every
metal ion and therefore is (I imagine) a rod shape (although unsaturated fats will produce a spiral galaxy shape...not sure what to call that)with two
hydrophobic ends, and therefore is water insoluble. In a few days, remove the soap from the mold (tear away the pringle can or other improvised mold,
if it is a contained shape) and cut into bars. Place these in a well ventilated place for two to four weeks to allow the saponification to come to
completion. The surface exposed when poured will develop a film of sodium carbonate from air contact. Give away your very cheap gifts and save funds
for labware and chems.
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Dr. Beaker
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why all the bother to make soap? and in addition your soap, made from vegetable oil, is made from mostly unsaturated and polyunsaturated fatty acid.
those acids have low melting points and mixing them into the staight chains of parafin will destroy order that needed for good crystalization. soap
from regular soap bar is probably stearate or laurate i.e saturated faty acid salt, and the perfume smell is for free.
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UnintentionalChaos
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Well, why not the bother to make soap? it's another interesting reaction to follow. The low melting points are not something that crossed my mind,
however. (I could go find lard or tallow at a butcher and use that for a harder soap, however) Thus, I forsee another mess about to happen and more
heptane being used to wash everything afterward. My mention of fragrance is for making usable soap from starting materials (NaOH, water, and oil) if
one should be so inclined. I'm not sure if you were making a reference to that or not.
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Aqua_Fortis_100%
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| Quote: | originally posted by Greenhorn82 :
I used to enjoy making nitroglycerin and nitrocellulose, but I got bored of it. Too much work, and not a good way to detonate it. Now I'm having fun
with thermite.
You can get the ingredients and pre-mixed thermite easily from eBay. I recommend using black iron oxide rather than red, because it burns much more
vigorously. It's hard to find good aluminum powder unless the store specifically sells it - I don't believe in buying an etch-a-sketch or grinding up
aluminum powder. You won't get a good reaction with it, and it's too much work. Just get it from eBay or a science shop (eBay is probably cheaper.)
Iron oxide, on the other hand, is easy to make. Buy some super-fine steel wool, stack the biscuits into bales and ignite it. It should glow for a good
15 minutes. When it cools, crush it into powder. The stuff that doesn't crush (mostly on the outside of the bale) is not fully oxidized, so don't try
to use that.
Or you can get chromium oxide and make thermite with that. It's also very fun. I'm thinking of trying some other metal oxides sometime.
I also just made some "rose" metal, which is a mixture of bismuth, lead and tin. It's not a chemical reaction or anything, but it's fun to play with.
It's an alloy that you can, if you're careful, stick your finger in when liquid, since it melts at below the boiling point of water.
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yeah.. aluminothermy is a very nice reaction.. You will enjoy which a CuO/Al or PbO/Al thermite can will do...
(i tried several times with PbO , but only now worked nice.. and very nice.. mine CuO/Al is too fast as flash powder and can also even explode if
confined..
but i never tried with chromium oxide...
| Quote: |
originally posted by Dr. Beaker :
as a high school student I made Pb, Cu soaps by mixing CuCl2 or Pb(NO3)2 with soap solution, and disolved it in parafin. I made a candle from it and
the Cu candel burned with a beutifull green color + red Cu metal acumelated on the roap-like cloth that carry the parafine(don't know the word for it)
the Pb candel was interesting in that it produced shining dropletes of Pb metal that "digged" inside the parafin because of the heat. hwever, because
of the poisoness of lead I would do it in a well ventilated place.
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wow is a nice idea about soaps and candles.. i dont know much about soaps (isn't a Pb based soap a bad idea for health??), but i made some years ago
some candles for sale it.. the Cu green flame is a nice idea.. thanks..
"The secret of freedom lies in educating people, whereas the secret of tyranny is in keeping them ignorant."
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UnintentionalChaos
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Upon much more careful solidification of the wax/soap mix, it is quite rigid and just a tiny bit tacky. I was throwing candles in the freezer to
hasten their solidification (which seems to work just fine with plain paraffin), but this seems to be unacceptable for the soap blend. I saw that the
blue flame from the candle is removed very quickly even with small additions of soap, but overpowering the yellow seems to require A LOT more. Did you
also notice that it crackles as the tiny deposited particles of copper burn?
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Aqua_Fortis_100%
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maybe..
sorry Uni, i have no paraffin at the moment to try..(when i will go in the art shop (to buy some stearin for my mill ,or ready fine Al powder, i will
remeber of this!)
maybe if very fine Cu powder is impregnated on candle "fuse", can gives a mild crackles effect and pale green flame(for Cu, for the salts can be nice
blue) i think..
| Quote: | | I saw that the blue flame from the candle is removed very quickly even with small additions of soap |
maybe the hydroxides (or another substance) from your soap can be reacting with Cu compound in candle, or to prevent which burns with the blue flame
. what about?
"The secret of freedom lies in educating people, whereas the secret of tyranny is in keeping them ignorant."
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UnintentionalChaos
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I'm not trying to make a blue flame. Normal candles will burn with some blue flame and some yellow. The point of adding copper soaps is that when they
burn, copper particles are released into the flame, changing it to a green color (standard color for copper non-halide complex compounds). A side
effect is that very fine copper particles are deposited on the wick and crackle as they are burnt into oxide. Perhaps this could be done intentionally
too, but I seriously doubt that a little copper powder can change the color of the flame. I've been doing another experiment with copper chloride to
try to make blue flames, by "basting" the wick repeatedly at intervals to allow drying with CuCl2 in alcohol until it is quite saturated. This, when
placed into a candle is not enough to change the flame color. I then tried using the wick, then a few quick dips of wax and rolling in more CuCl2 and
then repeating. 2 rolls in CuCl2 powder along with the wick produces small amounts of blue green flame (because CuCl2 is a halide complex salt
(chloride, flouride, iodide, bromide, etc.) With more repetitions, I should be able to make the blue-green more pronounced, though it will probably
never dominate the flame's color.
Also, I imagine the lead soap candle would be an interestingly dangerous experiment. As was mentioned before, LOTS of ventilation for that one. Of
course, any (that I know of) soap that is not an alkali metal soap (not made with sodium or potassium, the standards for making soaps for washing, or
technically lithium, rubidium, or cesium (no way I'd waste those anywhere near soaps...well maybe lithium for a candle type experiment) will be water
insoluble, and obviously not for washing one's hands
There should be minimal hydroxides left in the candle as they attach to the glycerol to make glycerin and are washed away (mostly) when I melted the
soap in a water bath to wash it. You misunderstood the problem a bit there.
PS: I'm starting to wonder if it is even possible to get a true green flame from this or if it will always be quite yellow. The crackling is quite
neat, though Maybe I should try starting with a potassium soap instead to avoid
possible sodium contamination.
[Edited on 1-5-07 by UnintentionalChaos]
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