What does a reaction between concentrated H2SO4 and a solution of NaCo(NO2)6 and NH4cl produce?

i was in my chem lab today and had a test tube that contained a solution of Ammonium Chloride (NH4Cl) and Sodium Cobaltinitrite (NaCo(N02)6 and instead of disposing of it i decided to pour a little bit of 18 molar sulfuric acid to it (Horrible Idea!!!). anyways i cant figure out what kind of gas the reaction produced but i think it might have been nitrous oxide because i guess i breathed some in and i almost ped out and my heart started racing. it was a really scary experience.