Random
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phosphorus from matchboxes
I have tried filling a tuna can with MEK and soaking, then scraping the matchboxes.
Red phosphorus seems to get off easily but a significant amount of paper does too. I guess paper is cellulose so what would be most efficient way to
get rid of cellulose and acquire clean RP?
I was thinking about schweizers reagent but I'm inexperienced with it, how effective it is. I want to dissolve all of cellulose and leave RP intact.
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bfesser
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When discussing phosphorous and it's various allotropes, please try to avoid 'k3wlishness'. This discussion
is fine for now, but any more 'k3wlisms' will land it in Detritus. Just a preemptive warning.
Call it butan-2-one (IUPAC), 2-butanone, or just butanone; MEK is essentially a layman's term—how they label
paint stripper cans for dummies. We are amateur chemists, not amateur painters. Also, using a tuna can is exceedingly amateurish. Don't you own any
beakers? If not, at least try to keep the discussion at a little higher level.
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bfesser
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Thread Moved
18-9-2013 at 08:05 |
elementcollector1
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Names are a tricky and changeable thing, especially when it comes to IUPAC.
Back on topic, the paper is best dissolved in a wash of boiling, concentrated hydrochloric acid followed by acetone or some other such solvent. If you
want to, you could try Schweizer's Reagent, but I find it's a little slow.
[Edited on 18-9-2013 by elementcollector1]
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woelen
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Scraping red phosphorus from match boxes is crap and you can hardly expect any decent results. The red P is contaminated with paper, very fine
sand/glass, possible some antimony sulfide and binder. Besides that, you need a LOT of boxes to get even a tiny amount of red P.
@bfesser: the term "MEK" is not a k3wl-term for butanone, it stands for Methyl Ethyl Ketone and (at least where I live) this is an accepted acronym,
also in circles of professional chemists. It maybe is a trivial name, or an old name, but not a kewl-word. The use of old terms is not always a bad
thing, sometimes the new official terms are alienating very much, e.g. the ion S(2-) is called "sulfanediide", e.g. Na2S should be called sodium
sulfanediide, but who does this? Everyone, even professionals, use the name "sodium sulfide". Another one is H2S, which should be called sulfane,
while even wikipedia uses the much better term "hydrogen sulfide" instead. The term sulfide only tells that there is sulphur in the compound, but
tradition is strong and every person with some chemistry background understands the traditional name. Another example is ferrocyanide and
ferricyanide, instead of hexacyanoferrate(II) and hexacyanoferrate(III).
I agree with you that talking about using a tuna can does not sound very professional. It sounds like cookery and messing around with chemicals.
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Random
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I have chosen tuna can because it was not a tall container so I could easily put a small amount of 2-butanone into it, using a plastic container would
not be the best option, as far as I know solvents are usually in metal storage containers.
It's not the best option but I have a fairly large amount of those matchboxes and didn't want to start a "kewlish" discussion at all. Just wanted a
simple solution to get rid of paper and leave RP. RP is also a versatile reagent in organic chemistry, you can't just say it's one use. I have seen
numerous syntheses with RP as a requirement.
The matchboxes I have have a thick coating of it and it seems to give decent yield. Unfortunately I have no professional chemistry glassware and I
have to use household things. I don't see any problems in that.
It seems that handling hot conc. HCl is much more dangerous that schweizer's so I'm gonna try that route though.
By the way tuna cans are made of iron which is pretty good for neutral and alkaline high temperature reactions.
[Edited on 18-9-2013 by Random]
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DraconicAcid
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Organic solvents don't react with most metal cans, but you'd still be better off using glass. Old jars generally work fine.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Mesa
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Quote: Originally posted by bfesser  | | We are amateur chemists, not amateur painters. Also, using a tuna can is exceedingly amateurish. Don't you own any beakers? If not, at least try
to keep the discussion at a little higher level. |
| Quote: | | Mad Science is about exploring and manipulating aspects of the natural world without the facilities or resources of "sane science" as practiced in
academic, industrial, and governmental research settings. Mad Scientists must generally pay for expenses out of their own pockets, which may not be
very deep. Because of these financial constraints they must work without the extensive and expensive equipment available in a real lab. As annoying
and potentially hazardous as it is, for most Mad Scientists the lab is a shed, basement, bedroom, or garage, and the fumehood is the great outdoors.
|
MEK(Syn: Methyl Ethyl Ketone) is the way I have always, and will always refer to this. There is a difference between kewlism and efficiency.
Do you call vinegar Ethanoic acid in casual conversation?
The OP is discussing the use of a fairly specialized solvent in order to dissolve a substance that is notoriously difficult to remove, how much
'higher' do you expect from a post in the "beginnings" forum?
@OP: You may want to look at some lab preparations of microcrystalline cellulose from paper, it may give you some ideas to help. However if I wanted
P4 that badly, I'd probably just electrolyse Copper/Phosphorus brazing rods. Although I have no references nor experience so due diligence in
studying the potential dangers would be required, I just remember reading the MSDS of said brazing rods when doing workshops for mechatronics
engineering and seeing Red Phosphorus making up about 10% of the weight.
[Edited on 18-9-2013 by Mesa]
[Edited on 18-9-2013 by Mesa]
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Fantasma4500
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acetone works aswell, it just needs to dissolve the glue / binder that sticks the RP to the paper
just add a few drops with a pipette or whatever, then scrape it off with a knifeblade thats not ultra sharp, the flatter it is the better
this wont be pure at all anyways
i suppose why all the paper came off was because it was soaked in the liquid
if you scrape the pieces of red phosporus you get into a container with some acetone (excess) and make it all a powder in there, that should dissolve
all the glue, and you could then decant off the glue / acetone and leave the red phosphorus to dry
keep in mind RP can ignite due to friction
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elementcollector1
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| Quote: Originally posted by Antiswat | acetone works aswell, it just needs to dissolve the glue / binder that sticks the RP to the paper
just add a few drops with a pipette or whatever, then scrape it off with a knifeblade thats not ultra sharp, the flatter it is the better
this wont be pure at all anyways
i suppose why all the paper came off was because it was soaked in the liquid
if you scrape the pieces of red phosporus you get into a container with some acetone (excess) and make it all a powder in there, that should dissolve
all the glue, and you could then decant off the glue / acetone and leave the red phosphorus to dry
keep in mind RP can ignite due to friction |
Turns out acetone isn't that good at dissolving paper. If it does, it does it so slowly that it's simply not a good method.
I used about 25 matchboxes, totaling 50 strikers, and received less than half a gram of phosphorus. Good enough for an element sample...
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bfesser
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| Quote: Originally posted by Random | | By the way tuna cans are made of iron which is pretty good for neutral and alkaline high temperature reactions. |
They're typically made of steel and coated (at least on the inside) with a protective layer of
<em>x</em>.<sup>1</sup> They are <em>never</em> made of plain iron. They're damn handy as disposable cups for
paint and strippers, though!
Note: <em>x</em> varies, depending on the intended contents. For tuna; likely a phenolic epoxy
blend.<ol><li><strong><a href="http://www.inderscience.com/www/pdf/2012ijtpm_lakind_openaccess.pdf" target="_blank">Can
coatings for foods and beverages: issues and options</a></strong> <img src="../scipics/_pdf.png" /> — J.S.
LaKind</li></ol>[edit]
<strong>woelen</strong>, I have no problem with "MEK". But it never hurts to use good nomenclature.
<strong>mesa</strong>; yes and no. I often speak/write <em>ethanoic acid</em>, depending on the context and audience. I
never refer to vinegar as ethanoic acid, though—it's a food. This is a chemistry forum, not a grocer or hardware store—so you may
see me write things like "ethanoic acid" or "butan-2-one." Honestly, in this case, I don't really care. I was just trying to avoid another 'Red P
for k3wls' thread—so just relax.
[Edited on 20.9.13 by bfesser]
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Bot0nist
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There are much better OTC sources of nearly pure "RP" here in the states than matchboxes... And in not talking about a complicated isolation from
brazing rods either.
Acetone does do the trick though for match strikers, and the way to go is as Antiswat described. Just wet the strips with acetone, and lightly scrape
it off. Use excess acetone to decant most of the glue off. It will still have glass and sand and other shit in it though, but it worked for a very
small amount of Armstrong's though. Not sure about regeneration of HI for organic synthesis though, but it must work for the tweakers, or other uses
when purity isn't a concern. I just couldnt stand processing tons of little match strikers for a few grams of impure red phosphorus...
Also, I don't blame bfesser for being cautious, given the enormous amount of "kewl" or cookery topics about matchbox scraping on the net...
[Edited on 20-9-2013 by Bot0nist]
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