The answer
12,3 mol of NO reacts with 8.2_mol of ammonia
5.87 mol of NO yields 4.89_ mol nitrogen
Proof
This kind of question is called mole-mole problem, for solving it we process as follow
4 NH3 (g) + 6 NO (g) ----> 5 N2 (g) + 6H2O
4moles 6moles
X ---------------12.3 moles
This implies x=12.3 x 4 /6=8.2 moles, so 12.3 moles of nitrogen corresponds to 8.2 ammoniac
4 NH3 (g) + 6 NO (g) ---> 5 N2 (g) + 6H2O
6 moles 5moles
. 5.87 moles---- x=?
After cross-multiplication,
5.87 x 5 / 6 = 4.89, so 5.87 moles of nitrogen oxyde yelds 4.89 moles of nitrogen