Sciencemadness Discussion Board

Disposal of conc. nitric acid

Sarafan - 21-12-2011 at 19:36

Some time ago, i bought 500 g of nitric acid from a chemical provider for schools. Since it didn't say how concentrated it was, I tried to do a titration, measuring 10 ml of it in an erlenmeyer.
However, when I put the colourless nitric acid in the container, it almost immediately turned yellowish (I gather that i'ts because of the NO2 and NO that contaminate it), and then I was how the brown NO2 gas started forming in the erlenmeyer. Fearing this, I cancelled the titration, disposed of the acid and ventilated the room.

Anyway, since the acid did not cost much, I was wondering which would be the best way to dispose of it safely. I may try to titrate it again diluting it first, but in any case I don't want any strong or dangerous acids at home. I saw some vapor coming out of the jar when I opened it, so would that mean that i'ts fuming nitric acid? in that case, how would you recommend me to dispose of it?

I've seen in some other posts that at least in the US there are waste processing facilities that receive dangerous waste. However, I'm argentinian, and I don't think we have those kind of facilities here. Therefore, I need to do it myself!

Thanks!

Bot0nist - 21-12-2011 at 20:15

Neutralize it into something usefully. Got any ammonia, KOH, or NaOH?

MagicJigPipe - 21-12-2011 at 20:19

First, try as hard as you possibly can to get it to someone that does want it.

Second... Just pour it down the drain slowly with LOTS of water if you MUST get rid of it.

Please don't waste resources and time by taking this to a treatment facility. In order to determine if it's okay to pour something down the drain, just think about it: I simply can't imagine a scenario in which pouring any kind of typical acid, whether strong or not, would be more detrimental than, say, the drain cleaners that people use on a regular basis. After it's done reacting you will have a myriad of nitrated organic products and nitrate salts in the sewer system. By the time it gets to a treatment facility (if they use those there, I'm not sure) virtually none of the original acid will remain. No --- Big --- Deal.

EDIT

Yes, or do what b0tonist recommends.

[Edited on 12-22-2011 by MagicJigPipe]

Sarafan - 21-12-2011 at 20:23

I've got some NaOH. The ammonia I've got is just household ammonia, not pure at all.

in that case, if I could titrate it and know the concentration, i could neutralize some of it to get NaNO3 (I dont want to use all my NaOH). Then, I could just dilute the remainig acid or neutralize it with NaHCO3.

I i did taht, would I get NaNO3 right?

HNO3 + NaHCO3 --------- NaNO3 + CO2 + H2O

Sedit - 21-12-2011 at 21:18

How are you Titrating it? I am curious as you seen NOx fumes the first time yet you have never tried to neutralize it with any base...

What is your process for Titration?

AndersHoveland - 21-12-2011 at 21:26

So unfortunate that the nitric acid has to go to waste. Could not you find a local amateur chemist through the internet willing to take it from you?

hissingnoise - 22-12-2011 at 03:59

A SciMad trend well and truly bucked . . . ?



MagicJigPipe - 22-12-2011 at 11:11

Could you please elaborate on your statement, hissingnoise. I don't understand.

AndersHoveland - 22-12-2011 at 11:24

Ferrous sulfate, FeSO4, if initially added to concentrated nitric acid, can reduce most of the nitric acid to nitric oxide, continuing the reduction even after the concentration of the acid falls to dilute levels, because the presence of NO is able to effectively catalyse the reduction of dilute nitric acid.

(6)Fe[+2] + (2)HNO3 + (6)H[+] --> (6)Fe[+3] + (4)H2O + (2)NO

hissingnoise - 22-12-2011 at 13:18

It's just a throwaway remark MJP - I had to laugh seeing as how many here are consumed with getting their hands on as much HNO<sub>3</sub> as they possibly can . . .



entropy51 - 22-12-2011 at 18:45

Quote: Originally posted by hissingnoise  
It's just a throwaway remark MJP - I had to laugh seeing as how many here are consumed with getting their hands on as much HNO<sub>3</sub> as they possibly can . . .


Given the ready availability of KNO3 stump remover and H2SO4 drain opener, anyone who can't make HNO3 probably doesn't need HNO3.

I neutralize waste acid with washing soda (Na2CO3) which is sold in the grocery store and not terribly expensive. Beware the foaming due to CO2 formation however.

jsc - 23-12-2011 at 12:56

First you need a hazmat suit, preferably one of the ones with the scary looking nozzle where your mouth is.

LOL, something needs to be done about chemical hysteria. The world is lumbering towards thermonuclear armageddon and people are worried about the "proper" way to dispose of walnut shells.

hissingnoise - 24-12-2011 at 04:11

Quote:
Given the ready availability of KNO3 stump remover and H2SO4 drain opener, anyone who can't make HNO3 probably doesn't need HNO3.

Distilling acid gets to be a pain in the arse depending on what else you're doing - I'd prefer to be able to buy the stuff . . .