Answer:
O₂ is the limiting reactant
0.406 moles of ammonia remains after the reaction goes complete.
Explanation:
Balanced reaction is:
4NH₃ + 5O₂ → 4NO + 6H₂O
Let's determine the moles of each reactant:
12 g . 1mol / 17g = 0.706 moles of ammonia.
12 g . 1mol / 32g = 0.375 moles of oxygen.
4 moles of ammonia react to 5 moles of oxygen
Then, 0.706 moles of ammonia may react to (0.706 . 5) /4 = 0.882 moles
We only have 0.375 moles of oxygen and there are needed 0.882. O₂ is the limiting reactant. Definetely ammonia is in excess.
5 moles of oxygen react to 4 moles of ammonia
Our 0.375 moles may react to (0.375 . 4) / 5 = 0.3 moles
We have 0.706 moles of NH₃ and we only need 0.3
After the reaction goes complete (0.706 - 0.3) = 0.406 moles of ammonia still remains.
