toothpick93
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White Phosphorus from Phosphoric Acid
A fellow youtuber sent me a message recently saying it possible to use Phosphoric Acid to get White Phosphorus. I was interested by this because i
thought you cant use phosphoric acid to make white phosphorus. He said make Trisodium Phosphate, then bubble chlorine gas through the solution and the
chlorine (as the stronger oxidizer) replaces the phosphorus in solution causing the phosphorus to fall out... is this true? I somehow dont rekon. What
do you think>
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IrC
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I think before asking this do a search for an already long thread where your questions are already answered. Started by Polverone IIRC. Also many
details pertaining to safety from the experiences of others is useful reading in it. Always better to copy a working wheel instead of inventing it all
over again.
http://www.sciencemadness.org/talk/viewthread.php?tid=65
There I did your work for you, did you not see the 4th sticky down in this very section?
[Edited on 4-10-2013 by IrC]
"Science is the belief in the ignorance of the experts" Richard Feynman
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toothpick93
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What page is this idea that i posted on, it will take along time to look through the whole thing, i just really wanted to know either yes it works,
no it wont, or yes but its more complicated
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woelen
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Quote: Originally posted by toothpick93  | | A fellow youtuber sent me a message recently saying it possible to use Phosphoric Acid to get White Phosphorus. I was interested by this because i
thought you cant use phosphoric acid to make white phosphorus. He said make Trisodium Phosphate, then bubble chlorine gas through the solution and the
chlorine (as the stronger oxidizer) replaces the phosphorus in solution causing the phosphorus to fall out... is this true? I somehow dont rekon. What
do you think> |
If you have a little understanding of chemistry, then you would immediately say that the
answer is NO, a strong NO!
Chlorine is a strong oxidizer and phosphorus is a strong reductor, so what would happen if chlorine and phosphorus come in contact with each other? A
violent reaction (even fire). Chlorine and phosphorus cannot coexist and in the presence of water they react to form phosphoric acid and hydrochloric
acid (and maybe some phosphorous acid as well if not sufficient chlorine is used). If you already have phosphoric acid and you bubble chlorine through
this, then nothing is there to be oxidized, everything already is oxidized to the max. Chlorine simply bubbles through the solution and does nothing.
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IrC
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Have you even tried entering the title of this thread into a search of this section? You missed my point about learning details by study of the work
of others. Little things like under what conditions might you unknowingly be producing such things as Phosphine, or POCl3, or etc..
Do some reading for a while.
"Science is the belief in the ignorance of the experts" Richard Feynman
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toothpick93
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Thank you woelen, That answers my question. I know people dont like people starting new posts on topics already discussed, but just a simple answer
like that closes the thread. I had very low doubts it would work, i know there is not much interesting experiments with phosphoric acid, os when this
question was told to me, i knew it want going to be true. Was too easy
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MrHomeScientist
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There's also the short questions thread stickied in the Miscellaneous section for simple questions that you only want a yes or no answer to. Might be
worth looking at!
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AJKOER
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| Quote: Originally posted by toothpick93 | | A fellow youtuber sent me a message recently saying it possible to use Phosphoric Acid to get White Phosphorus. I was interested by this because i
thought you cant use phosphoric acid to make white phosphorus. He said make Trisodium Phosphate, then bubble chlorine gas through the solution and the
chlorine (as the stronger oxidizer) replaces the phosphorus in solution causing the phosphorus to fall out... is this true? I somehow dont rekon. What
do you think> |
High temperature preparation (1500 C):
2 Ca3(PO4)2 + 6 SiO2 + 10 C → 6CaSiO3 + 10 CO + P4
---------------------------------------------------------------------
I read in an old text that H2 generated in situ by an acid on zinc was able to partially reduce phosphorous acid, H3PO3, forming some PH3. A quote:
""...it is known that phosphorous acid reduced with nascent hydrogen, yields phosphine and hypophosphorous acid"
Source: "investigation of sodamide and of its reaction-products with phosphorus" William Phillips Winter p42-43
Now, the action of nascent H2, or H2 formed in an electrolysis of H3PO4, could form H3PO3.
Then, per Wikipedia:
"Phosphorous acid on heating at 200 °C converts to phosphoric acid and phosphine:
4 H3PO3 → 3 H3PO4 + PH3"
Then, the thermal decomposition of PH3 at 680 C:
4 PH3 (g) --> P4 (g) + 6 H2(g)
Still a hot and toxic route to P.
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