kevinlimse - 12-9-2004 at 22:18
4 M of NO2 is liberated after heating a NO3- compound. Anyone knows how to test and identify the Gas NO2?
frogfot - 12-9-2004 at 22:47
By its color 
Letting it through water to make colorless NO, and then letting it out into air to reoxidise brown NO2. Not many gases can do that...
Esplosivo - 12-9-2004 at 22:48
There are various tests you can carry out to identify NO2 gas or its ions.
NO2 gas decolourizes Potassium Manganate (VII)
If aqueous iron (II) sulphate in dilute sulphuric acid is mixed with a nitrite salt a dark brown complex ion is formed - Fe(NO)2+
Nitric (III) acid, forme by bubbling NO2 through water appears as a pale blue solution, decomposing to give brown fumes of NO2
Hope this helps