Question RED.P and time

[Pajmon]

Hi, does anyone have experience with red phosphorus and whether it loses its effectiveness over time, or something happens to it in the air. what does the humidity of the air do to it... Thank you for any answer

 

[fidelis]

"Freshly prepared, bright red phosphorus is highly reactive and ignites at about 300 °C (573 K). After prolonged heating or storage, the color darkens; the resulting product is more stable and does not spontaneously ignite in air," according to wikipedia :] additionally, humid storage conditions can cause the release of phosphine (which is toxic). try using a dehumidifier maybe?

 

[Pajmon]

Thank you for the reply, and yes that's exactly how it is the color already dark red.. I've had it for about 5 years. Is there any difference in the reaction when I pose new or old? And another thing that interests me in phosphorus are small black crystals, does anyone know what it could be? Thank you

 

[fidelis]

no problem :] sorry, i didn't see this until a few days later. i would use new if i were you but i don't know if it makes a difference in the reaction as i haven't done it firsthand. i'm not sure what the black crystals are. when i went to google, it said it might be black phosphorous, also known as "phosphorene", but idk if it's actually that. personally i would ask one of the experts on the sidebar ^_^

 

[Pajmon]

Who would you recommend? ́ ́product is more stable ́ ́ does it mean that it reacts worse? What do you think?

 

[fidelis]

i would recommend @William D. or @G.Patton

also i would assume that's what it means

 

[G.Patton]

I guess, your phosphor is already spoiled and it's worth to buy new one. 5 years with air exposure - sounds like it's done.

 

[Pajmon]

Thank you. I also assumed that it would be so. I don't have any other at the moment. Don't know if it can be revived? or use it more?

 

[G.Patton]

I think it would be easier for you to get a fresh one.

 

[Pajmon]

I'm trying to find a new one, so far I'm not succeeding. Do you think if I used a larger amount the reaction would be successful?

 

[G.Patton]

I don't know.

 

[Pajmon]

I found something by googling so I'll share it : . Red Phosphorus. Commercial red phosphorus is purified as follows: Portions of 100 g. are boiled for 24 hours with a 7% NaOH solution. After removal of the hydroxide, the phosphorus is boiled for 24 hours with water, washed with cold water until the alkaline reaction disappears (a centrifuge may be used here to advantage) and dried in vacuum on clay plates over P3O5 . Phosphorus which has stood for some time must be freshly washed before use because of its oxidation on exposure to air.

 

[Pajmon]

I think that the purity of phosphorus is very important, I can have a phosphorus of 99 percent, but in 5 years it may be only 60 percent and it will not work properly. And it's hard to estimate how much to put him in response because I don't know what percentage he has.