Junk_Enginerd
Hazard to Others
Posts: 250
Registered: 26-5-2019
Location: Sweden
Member Is Offline
|
|
Nitric acid bottles growing exterior crystals?
I have a bottle of nitric acid that's started growing crystals after a year or so. It's mostly around the cap. This has me mildly concerned about what
it might be. This is most prevalent with my home made RFNA, my commercial 68% nitric acid is showing much less of this. What are these crystals? They
are translucent, long, thin and very fragile.
|
|
|
Bedlasky
International Hazard
Posts: 1219
Registered: 15-4-2019
Location: Period 5, group 6
Member Is Offline
Mood: Volatile
|
|
I don't know what the crystals are, but fuming nitric acid attack plastics. Even plastic caps from duran bottles are significantly damaged after a
month. Only ground glass flasks and glass ampules are suitable for long term storage.
[Edited on 21-1-2024 by Bedlasky]
|
|
|
Sir_Gawain
Hazard to Others
Posts: 272
Registered: 12-10-2022
Location: Due South of Due West
Member Is Offline
Mood: Yes.
|
|
Is it stored near anything volatile that could react with it, like ammonia? Perhaps it’s reacting in gas phase and depositing solids.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
It most likely is ammonium nitrate, or amine nitrates. If you have animals (pets!) around, then this is even more likely, due to presence of ammonia
or amines from these animals.
I would not worry about these crystals, no risk of explosion. Just wipe them off with a moist towel and rinse the towel with some water.
It, however, is an indication, that the acid is not stored well for long term storage. Fuming nitric acid is amazingly hard to keep around for a long
time. I would suggest to use it up quickly. It also is not safe to ampoule it, because the acid may decompose, with one of the decomposition products
being oxygen. That may lead to pressure buildup and explosion of the ampoule.
|
|
|
Junk_Enginerd
Hazard to Others
Posts: 250
Registered: 26-5-2019
Location: Sweden
Member Is Offline
|
|
Ahhh yeah of course. I was wondering what on earth the supposed NO2 could be forming salts with just out of thin air, but ammonia seems reasonable.
Googling ammonium nitrate crystals supports this as well, it looks very similar. And yeah, I have ammonia bottles in the same space, and a kitty
litter box nearby too lol. Mystery solved!
|
|
|
Raid
Hazard to Everyone
Posts: 201
Registered: 14-11-2022
Location: N/A
Member Is Offline
Mood: School
|
|
Any pictures of the crystals?
|
|
|
Tsjerk
International Hazard
Posts: 3022
Registered: 20-4-2005
Location: Netherlands
Member Is Offline
Mood: Mood
|
|
I just noticed my bottle of 96% sulfuric acid is 'sweating'. The bottle is in a cupboard in a unheated shed here in the Netherlands. I didn't touch it
in two years.
I expect the bottle to have heated 20+ degrees at least 10 times now. The bottle is 2.5 liters, with at least 1.5 liters head space. The 'sweat' is
acidic, but only slightly. I expect it to be a couple percent sulfuric acid, the acid was released during hot days and will never evaporate,
attracting a lot of water while being there.
[Edited on 3-2-2024 by Tsjerk]
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
