Sciencemadness Discussion Board

Identification of mist from a leaking/gassing acid bottle

dangerous amateur - 14-4-2021 at 08:10

I've got a plastic box with several bottles of several different acids.
Mostly nitric and sulphuric.
(But no HCl)

Now the plastic box starts a little warping, the labels on the bottles turn brown and fall off, and a wet smear covers the hole thing.

Nothing really bad, but I like my stuff clean and also I dont like my acids thinned over time.

Assuming it's either nitric or sulphuric:
What would be your prefered technique to analyse the mist layer and find out what it contains?

njl - 14-4-2021 at 08:18

Mix with calcium salt. But sulphuric acid is relatively non-volatile compared to nitric acid so I would put my money on nitric.

dangerous amateur - 16-4-2021 at 01:12

Sadly I only have the chloride ;)

But when I wipe a little of this mist into a piece of paper and squeeze the paper out with some additional water, do you guys think that this will be enough to be detected by a brown ring test?

dangerous amateur - 18-5-2021 at 06:18

Somehow I messed up the ring test or the concentration was to low.

Meanwhile I have singled out two suspicious bottles of nitric acid.
They definitely throw mist on their surroundings.

But which one is it...?

It takes months to build up enough mist that I can clearly see it.

I have some litmus here. If I create a solution and place that openly together with the nitric flask into a bag or something, do you think this would be sensitive enough?
I cant find my strips at the moment, but placing a strip inside the bag will probably solve the question, would this show something with gas contact only?

[Edited on 18-5-2021 by dangerous amateur]

Fyndium - 18-5-2021 at 06:42

You might wanna check the caps and seals of the bottles, and replace them, especially with nitric acid and other badasses. Sulfuric acid is basically not volatile, more you'd be worried other things being volatile towards it, like water that it likes to absorb as one of the best desiccants there exists.

You could also get big enough ziploc bags and seal all or part of the bottles into those, and see if the problem disappears. I store almost everything in ziplocs nowadays, including my glassware, helps organizing and also protects them from others, and others from them.

Sulaiman - 18-5-2021 at 14:28

If you have some, you could put some ammonia near to the suspect bottles as a white ammonium nitrate will form when ammonia reacts with nitric acid.

dangerous amateur - 28-5-2021 at 14:16

The PH strip method worked.
Both indicated acid, but one was much faster than the other.

Both bottles got PTFE caps now.

Unfortunately the 68% acid is now around 55%.

RustyShackleford - 28-5-2021 at 15:47

I have seen that in another persons storage with nitric acid (and also in separate incident with HCl). so in your case it sounds like its the nitric doing it