Melgar
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Lightning in a bottle
So, I was cleaning out glassware, when I came across one with some cruddy stuff floating around in the bottom. A few rinses with water didn't get rid
of it, so I squirted in some hydrochloric acid, assuming it was some metal powder or oxide. That didn't do anything. I had some used piranha
solution from cleaning out other glass, and added some of that, figuring the combination would dissolve it for sure. Nothing. Maybe the peroxide was
spent? I added a bit more. No reaction. So I took a closer look at it. Oh, phosphorus, right. Perhaps 10-20 mg total. Well, there's not much
that phosphorus reacts with besides halogens, but I did have a wash bottle full of bleach. I figured I'd use it to neutralize the peroxide, then it'd
react with acid to form chlorine, which would stay in solution due to the high concentration of chloride ions. Chlorine + phosphorus + water =
phosphoric acid and HCl, both of which are very soluble in water. Seemed like it'd work, and due to the tiny amount of phosphorus, I wasn't worried
about anything blowing up on me. So I squirted some bleach in, and of course, O2 bubbles. Squirted some more in, until the bubbling wasn't as
vigorous, then swirled it around.
There were sparks.
Wait, what? Sparks!? I tried it again. Yep, sparks. Definitely sparks. Oh right. Phosphorus burns easily. I'm generating O2 here. Chlorine can
ignite phosphorus. Still, I was surprised how bright they were. I turned out the lights, and it was even more impressive. A squirt of bleach and a
swirl of the bottle, and there was a lightning storm inside it. From that tiny amount of phosphorus, no less. I set it down, finished up what I was
doing, and came back to it. But this time, there were no sparks. The reaction that I had been counting on to dissolve the phosphorus had run its
course. Well, that was that. It was pretty cool while it lasted.
The first step in the process of learning something is admitting that you don't know it already.
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woelen
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Yes, phosphorus and chlorine is an impressive combination. Based on this observation I designed a small, but very impressive experiment which works
extremely well as an eye catcher and for raising interest in chemistry in young kids:
http://woelen.homescience.net/science/chem/exps/chlorine_fla...
If you don't have potassium nitrate, this also works with sodium nitrate, potassium perchlorate or calcium nitrate). Do not use chlorates, mixes with
that can ignite even by light friction!
If you don't have aluminium powder, this also works with magnesium powder or magnalium powder. It also works with sulphur or powdered sugar or simply
with more red phosphorus in it, but in these latter cases, the flashes are less impressive. The metal powder makes the reaction spectacular.
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Melgar
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Interesting. Would potassium permanganate work instead of potassium nitrate? I've used that as flash powder, and it's certainly impressive. I don't
actually have potassium nitrate, although I do have nitric acid and potassium hydroxide, so it's not like I'd have to buy any. I was searching for a
reaction to use for comedic effect in a safety video. The more energetic and bizarre, the better. My first thought was LiAlH4 + water. It explodes
with a loud bang. (Like 30 mg or so, not dangerous amounts.) Of course, loud noises aren't picked up by microphones very well, so a more visual
reaction might be better. It would have to react when liquid is dripped on it, and it'd be better if it wasn't instant. Iodine + aluminum powder
looked pretty bizarre in the youtube videos I saw of it. I was thinking of trying potassium permanganate + aluminum, then dripping glycerin on it.
If I remember right, that'd smoke, then ignite, then flash, no?
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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j_sum1
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I was thinking of doing the classic lightning in a test tube demo this week -- a layer of sulfuric acid topped by ethanol and then potassium
permanganate sprinkled in.
I might have to try this variant as well.
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Sulaiman
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Methylated spirits works well for the classic lightning in a test tube demo ,
... assuming that you want to save your ethanol.
CAUTION : Hobby Chemist, not Professional or even Amateur
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woelen
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Potassium permanganate and aluminium also can be used, but I'm not sure how friction-sensitive a mix with permanganate and red phosphorus is. I never
tried. If you try, be very careful when mixing the chemicals and do not prepare more than 100 mg quantity in total!
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j_sum1
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Quote: Originally posted by Melgar  | | So, I was cleaning out glassware, when I came across one with some cruddy stuff floating around in the bottom. A few rinses with water didn't get rid
of it, so I squirted in some hydrochloric acid, assuming it was some metal powder or oxide. That didn't do anything. I had some used piranha
solution {snip} rest of procedure... |
I tried duplicating your procedure but without effect. Admittedly I did not spend a lot of time on it. But I was looking forward to seeing those
sparks.
I might have to try again.
It occurs to me that if this can be made to work reliably, since such a small amount of P is used, it might be possible to simply use matchbox
strikers. That makes for a nice little dramatic experiment/demo with OTC items.
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Melgar
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To be fair, I have no idea what was in the used piranha, although it was green, so there was probably a nickel and/or copper salt. Also, the bleach
was the 10% stuff for swimming pools. It's hypochlorite added to acidic peroxide solution containing a small amount of phosphorus powder (with copper
and/or nickel salts) producing both oxygen and chlorine. Since the phosphorus had been used, it probably would have been a much finer powder than
usual. Not sure if any of that is helpful, but it's what I remember.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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woelen
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Try the procedure with chlorine gas passing over a tiny amount of phosphorus. Even tiny spots will produce small fires and smoke.
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