nightflight - 21-3-2007 at 04:42
Hi,
I´ve recieved a bottle, but unroftunately the label is gone,
I only know that it´s HNO3, but not the concentration.
It´s yellow, and there´re fumes coming out of it, when pened, could it be 65% or does only >90% HNO3 prodice fumes?
Thanks,
nightflight
YT2095 - 21-3-2007 at 04:45
65% will fume also, it`s a reaction with air moisture that causes it.
if it`s Yellow though, it`s either quite old and been poorly stored, or it`s at a higher conc.
unionised - 21-3-2007 at 11:07
Weigh a known volume of it and look it up in density tables or, to get better precision with more hassle, titrate it.
Furch - 21-3-2007 at 16:17
60% HNO3 also fumes... The only reliable way to know the concentration is to titrate it with a base of known concentration.
garage chemist - 21-3-2007 at 16:56
Distill it and note the boiling point/curve. This will show if you have 65 or 99% acid and is easier and faster that titration or density
determination.
Azeotropic HNO3 will boil at 121°C, anhydrous HNO3 at 83°C.
[Edited on 22-3-2007 by garage chemist]
Fleaker - 22-3-2007 at 12:09
I don't know how slow you are with a titration, but if you have a standard base and the proper indicator and equipment, it's definitely the way to go.
Get four good numbers on it and one can easily determine from there. Much faster than heating up nitric acid.