Sciencemadness Discussion Board

Weird nitric acid after 2 to 3 months storage

Dragonjack12 - 21-7-2019 at 13:23

I had just moved my nitric acid bottle in my work space and notice that there was a whole bunch of solid stuff that seems to have precipitated out. Has anyone had this problem before? I'll test some of the properties of the solid in a little bit just want to make sure that when I redistill the nitric acid (its fuming) that the solid won't be flammable or something. The acid is stored in a glass bottle and the lid has not been damaged. There was foam over in the preparation of this acid but I redistilled after initial preparations so I don't think that it would be potassium sulfate. The acid was produced through the potassium nitrate sulfuric acid distillation method.

XeonTheMGPony - 22-7-2019 at 04:24

Yes! matter of fact I had exact same thing, seemed all most like a gell.

I suspect it was some carry over from distilling it of the salts and small contaminants in the condenser.

Herr Haber - 23-7-2019 at 00:23

Upon finishing a bottle many years ago I saw something inside.
It was a gel or snot like substance that had grown from one wall to the other.
Never knew what it was but still curious. Acid was bought.

XeonTheMGPony - 23-7-2019 at 04:43

Quote: Originally posted by Herr Haber  
Upon finishing a bottle many years ago I saw something inside.
It was a gel or snot like substance that had grown from one wall to the other.
Never knew what it was but still curious. Acid was bought.


Makes me feel better! I thought I screwed some thing up despite best efforts.

I wounder what it is, as I am fairly neurotic at cleaning my glass wear when running a synth

AJKOER - 23-7-2019 at 18:30

Need some ideas? A possible guess (speculation) would be an adduct, like O(2)NOOCO(2)-, created from say CO2 exposure (from boiling) and light (which may induce the formation of HNO4, peroxynitric acid). A proposed pathway to HNO4, starting with nitric acid in light is:

HONO2 + Light (lab light in particular) --> .OH + .NO2

HNO3 = H+ + NO3-

.OH + NO3- = OH- + .NO3

.OH + .NO3 = O(2)NOOH (peroxynitric acid)

O(2)NOOH = H+ + O(2)NOO-

O(2)NOO- + CO2 <--?--> O(2)NOOCO(2)-

which is speculation based on the reported formation of the adduct ONOOCO(2)(-) from peroxynitrous acid at https://www.ncbi.nlm.nih.gov/pubmed/12844299 .

Sulaiman - 23-7-2019 at 18:47

I suspect the storage vessels;
HDPE (or other plastic) bottles are good for shipping liquids as they are not as heavy or fragile as glass,
I prefer to transfer liquids from hdpe to glass vessels asap.

XeonTheMGPony - 23-7-2019 at 18:54

I use Amber glass bottles.

Arthur Dent - 24-7-2019 at 07:17

My original glass bottle from Anachemia is kept in a plastic bin, and aside from a few fumes collecting on the surface of the glass (the cap isn't fume-proof), the label is still in perfect shape and the HNO3 is still perfectly clear. I bought that bottle over 25 years ago (and it's still 3/4 full).