[Nitrogenplease24]

Hello. I'm attempting to produce pure nitrogen from sulfamic acid and sodium nitrite. Supposedly the products should be nitrogen gas, water and sodium bisulfate(aq). For some reason, I'm getting these orange/brown fumes coming from the reaction and a sulfer smell, which is telling me this is not pure nitrogen. Can anyone tell me what's happening here and how to extract my pure nitrogen? Maybe it's reacting too fast and the heat is vaporizing some of the undissolved sulfamic acid? Can I bubble this through a solution to purify it? Thank you.

[billnotgatez]

We might need more information
like how are you combining these
Are you heating this
Are you cooling the reaction
Are you adding one to the other drop wise
are you using any solvents
are you doing this in open container or have air in the system initially


I assume you are trying to do this reaction
NH₂SO₃H + NaNO₂    NaHSO₄ + H₂O + N₂
or
H₃NSO₃ + NaNO₂    NaHSO₄ + H₂O + N₂

Can we also assume you understand the properties of the reactants

For instance

Sulfamic acid
https://en.wikipedia.org/wiki/Sulfamic_acid
IUPAC name  Sulfamic acid
CAS Number  5329-14-6
Chemical formula  H₃NSO₃

Molar mass  97.10 g/mol
Sulfamic acid melts at 205C (401F; 478K)
  before decomposing at higher temperatures to
    H₂O, SO₃, SO₂, and N₂.
Appearance  white crystals
Solubility in water  Moderate, with slow hydrolysis

Sodium nitrite
https://en.wikipedia.org/wiki/Sodium_nitrite
CAS Number  7632-00-0
Chemical formula  NaNO₂

Molar mass  68.9953 g/mol
Melting point  271C (520F; 544K)
  Above 330C sodium nitrite decomposes (in air) to
    Na₂O, NO, NO₂
Appearance  white or slightly yellowish solid
Solubility in water
  71.4 g/100 mL (0C)
  84.8 g/100 mL (25C)
  160 g/100 mL (100C)

[javhert]

Pretty sure that the orange / brown fumes you see are nitrogen dioxide (NO₂). Something for you consider: nitrogen dioxide is quite toxic: its effects are delayed, so even when it isn't as irritating as, for example, hydrochloric acid, it can cause significant damage to the lung up until lung edema.

A fume hood could suffice if you're using minor quantities. For bigger ones, a scrubber is needed. Scrubbing nitrogen dioxide doesn't seem to be easy since it doesn't dissolve quickly in water, so you will need longer contact times that the typical gas washing bottle.