Sciencemadness Discussion Board - Advice on best bottles for 98% HNO3

Advice on best bottles for 98% HNO3

Tkuze - 22-5-2019 at 17:09

Hey guys,
I wanted some advice on what you find to be the best container for longterm storage of nitric acid. I have amberglass bottles with green PTFE coated caps, but i just checked in the fridge and one cap was yellow and leaking and basically destroyed. The other bottle had the cap perfectly in shape. I have a 1L aldrich bottle to hold a majority of it, but never use it to pour directly because it tends to want to not pour out perfectly into the grad cylinder. Any advice would be helpful. Im guessing maybe one of the green coated bottle caps was already compromised or something. I can post pics if needed

Pic

Tkuze - 22-5-2019 at 17:22

Pic

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Tkuze - 22-5-2019 at 17:30

Just to clarify, the green bottle cap on the amber glass bottle is the same as the destroyed yellow one( or at least they started out identical)

Sulaiman - 22-5-2019 at 18:04

I kept fuming nitric in a sauce bottle for two years with no problem,
http://www.sciencemadness.org/talk/viewthread.php?tid=90897
but generally it is best to make it just before you need it.

monolithic - 22-5-2019 at 18:34

The green caps have a soft PTFE disc in them, right? I'm surprised that they leaked if the lid was tightened.

Tkuze - 22-5-2019 at 18:49

Yeah i think this is rhe second cap that went bad. I lept the threading dry and clean and used parafilm to seal it. I really think it has some outside damage or small defect that allowed it to escape and eat the surrounding plastic. Its strange because the other cap is in perfect condition

Keras - 22-5-2019 at 20:48

I’d probably keep nitric acid in one of those old vintage glass bottles with glass stoppers former pharmacists used. You can find a few ones on eBay, and some even have”nitric acid” engraved on them!

Tkuze - 22-5-2019 at 21:05

Apocethary bottles! Yeah ill have to get amber glass ones.

Cezium - 23-5-2019 at 00:02

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Herr Haber - 23-5-2019 at 03:23

Quote: Originally posted by Tkuze

Yeah i think this is rhe second cap that went bad. I lept the threading dry and clean and used parafilm to seal it. I really think it has some outside damage or small defect that allowed it to escape and eat the surrounding plastic. Its strange because the other cap is in perfect condition

That happened to me because the pouring ring still had a small barb on it from manufacture. Vapors seeped through the space between the barb and the PTFE from the cap and ate the cap.
I now remove the pouring rings and use PTFE caps (not just a liner) with a conical seal.
The conical seal is only needed for things that are going to build up pressure.

draculic acid69 - 23-5-2019 at 05:04

Would a coke bottle not stand up to the hno3?

[Edited on 23-5-2019 by draculic acid69]

Herr Haber - 23-5-2019 at 05:20

Quote: Originally posted by draculic acid69

Would a coke bottle not stand up to the hno3?

[Edited on 23-5-2019 by draculic acid69]

Not for long

https://www.plasticsintl.com/chemical-resistance-chart

draculic acid69 - 23-5-2019 at 05:51

That list says sulfuric acid is fine with no rxn for PET.ive seen h2so4 seem fine at first but an HR later it started smoking and heating up and dissolved it's way out of the bottle and all over everything.it fucks with PET bottles.now that I think about it it was moflo drain cleaner with 10% dmso.dont know whether that makes a difference or not.

Keras - 23-5-2019 at 06:04

There’s quite a comprehensive references on various plastic resistance to a lot of chemicals here.

[Edited on 23-5-2019 by Keras]

Nitric Acid Storage Bottle

FloridaAlchemist - 23-5-2019 at 06:10

A common BOD glass stoppered bottle works well to store fuming nitric acid.

Dragonjack12 - 23-5-2019 at 06:23

You can by little PTFE stoppers on amazon that might fit on your bottle. It would probably be temporary but then your prepared for a future Incident too,

Tkuze - 23-5-2019 at 14:43

Thanks so much for your help. Ill look on amazon

sbreheny - 24-5-2019 at 19:39

I want to second the suggestion of the glass bottle with ground glass stopper. That's what I use (see first two photos). One caveat is that the bottle will develop a slight positive pressure, lift the glass stopper slightly, and allow some fumes to escape. You might be able to prevent this by using a Keck clip but I haven't tried.

At first I used FEP (highly chemical resistant, similar to Teflon) bottles, and they DO work, but I found that they are slightly permeable to HNO3 vapor AND they took on a frosted appearance after a while. I'm not sure if this is a direct result of HNO3 or if it is actually ammonium nitrate crystals deposited inside the plastic (it was stored near ammonia and would slowly develop ammonium nitrate crystals on the outside of the bottle). My last photo here shows two identical FEP bottles - one which was used to store fuming nitric acid and the other unused.

Regarding the melamine caps with the Teflon liner - I have used those on bottles of 70% HNO3 and it always degrades them eventually. I think it is a combination of the fact that HNO3 vapor hits them when you open and close the bottle, some HNO3 often remains on the lip of the neck of the bottle when you close them, and also I suspect that like FEP, PTFE is slightly permeable to HNO3 (even though it isn't attacked by it)

By the way, my HNO3 started out at 94% (measured by density) and very pale yellow, and has over the last 3.5 years partially decomposed so that there is dissolved NO2 in it, as you can see. It would be nice if the ground-glass stoppered acid bottle were made from dark glass as I think that reduces the decomposition rate.