Sciencemadness Discussion Board

How dangerous really is picric acid?

chemist1243 - 19-10-2020 at 05:37

Picric acid has always been one of those explosives deemed as rediculously sensitive and powerful. But its just not true unless the picric acid is almost completely dry. Ive done probably 50 tests on wet or slightly wet picric acid and its never detonated once. Ive hit it with hammers, taped it to firecrackers, shot it with rifles, etc.

Am I going crazy or does picric acid just not go off unless its completely dry? It seems that way. Obviously, its not smart to assume explosive wont go off. There’s always a chance, so i always did everything in 100mg or less quantities, so maybe thats the reason it wouldn’t go off. Can anyone confirm the lack of sensitivity in wet picric acid samples?

karlos³ - 19-10-2020 at 05:43

It is, for this purpose, shipped only wet, with a 50% water content or so.
But take a look at our wiki, under "explosive", there you will find your observations confirmed.

yobbo II - 19-10-2020 at 06:02


If stored in the wrong container is can be dangerous. Some metal picrates can explode easily.

There is a massive thread on it somewhere.
This may be it.

http://www.sciencemadness.org/talk/viewthread.php?tid=13187&...

yob

[Edited on 19-10-2020 by yobbo II]

karlos³ - 19-10-2020 at 06:22

I forgot to add the link, here is everything important mentioned, including the issue with metal containers(or metal containing lids): http://www.sciencemadness.org/smwiki/index.php/Picric_acid

caterpillar - 19-10-2020 at 13:58

Picric acid is not extremely sensitive. Slightly more than TNT. A small amount of TNP, wrapped in tinfoil, detonates under strong impact of a hummer. This is the way to understand, how much dinitrophenole present in it- if nitration was not complete, picric acid won't detonate. Some salts are more sensitive than pure TNP, some less (ammonium salt for example). You shoul avoid contacts of TNP with metals and AN.

Herr Haber - 19-10-2020 at 15:02

Quote: Originally posted by chemist1243  
Obviously, its not smart to assume explosive wont go off.


Indeed !
https://en.wikipedia.org/wiki/Oppau_explosion

j_sum1 - 19-10-2020 at 20:05

Quote: Originally posted by Herr Haber  
Quote: Originally posted by chemist1243  
Obviously, its not smart to assume explosive wont go off.


Indeed !
https://en.wikipedia.org/wiki/Oppau_explosion


I was thinking more of this one.
https://en.wikipedia.org/wiki/Halifax_Explosion

(Although the wikipedia page is a bit thin on these details, the cargo of the SS Mont Blanc included substantial amounts of both wet and dry picric acid.)

Herr Haber - 19-10-2020 at 22:02

Ah, but they only had to give it one try at Halifax.
In Oppau, apparently using explosives to break up AN had been done thousands of times.

I liked OP's comment as a reminder to always prepare for the worst.

chemist1243 - 21-10-2020 at 12:12

Quote: Originally posted by karlos³  
I forgot to add the link, here is everything important mentioned, including the issue with metal containers(or metal containing lids): http://www.sciencemadness.org/smwiki/index.php/Picric_acid


It’s funny you mention this. Once upon a time i was trying to make ammonium picrate from aqueous ammonia and picric acid(it didn’t work in the end) becuase apparently its more stable than picric acid. Long story short, for some reason which i cant recall, i ended up transferring the basic solution to a metal pot.

Immediately realized how badly I might’ve just fucked up. I worked up the balls to crash everything into a large 5 gallon bucket full of ice water to hopefully dilute the solution to a safe level. That was the end of it. Now looking back on it, the picric acid/ammonia solution was pretty dilute to start with, but I’m sure if i had let it sit for a few days I might’ve seen some dunnite/metal picrate formation. At the time I had just been getting into chemistry so it scared the ever loving crap out of me, and now i think it scares me a little bit more.

I never did get to watch those red needle crystals I’d seen in pictures begin to fall out of solution though ):

caterpillar - 21-10-2020 at 19:21

Quote: Originally posted by chemist1243  
Quote: Originally posted by karlos³  
I forgot to add the link, here is everything important mentioned, including the issue with metal containers(or metal containing lids): http://www.sciencemadness.org/smwiki/index.php/Picric_acid


It’s funny you mention this. Once upon a time i was trying to make ammonium picrate from aqueous ammonia and picric acid(it didn’t work in the end) becuase apparently its more stable than picric acid. Long story short, for some reason which i cant recall, i ended up transferring the basic solution to a metal pot.

Immediately realized how badly I might’ve just fucked up. I worked up the balls to crash everything into a large 5 gallon bucket full of ice water to hopefully dilute the solution to a safe level. That was the end of it. Now looking back on it, the picric acid/ammonia solution was pretty dilute to start with, but I’m sure if i had let it sit for a few days I might’ve seen some dunnite/metal picrate formation. At the time I had just been getting into chemistry so it scared the ever loving crap out of me, and now i think it scares me a little bit more.

I never did get to watch those red needle crystals I’d seen in pictures begin to fall out of solution though ):



Strange idea, mate. make slurry- picric acid with some water and add in small portions ammonium hydrocarbonate (or carbonate). Mix it with some plastic. When it stops hissing, the process is finished. A small excess of carbonate is useful- you are guaranteed that there is no free picric acid. When product is dry, you may add AN.

chemist1243 - 22-10-2020 at 07:01

I imagine that would work quite well. You can see what i was attempting to do in the video i link here. It seems to me he just added ammonia solution and it worked. I was much more naive back then however(i still am today), so even if it was bunk i probably was just too blind to realize it.