Answer is 2 : 1.
Explanation;
Reaction between NH₃ and O₂ can give N₂ and H₂O as products. The balanced reaction equation is
4NH₃ + 3O₂ → 2N₂ + 6H₂O
According to the balanced equation, 4 molecules of NH₃ react with 2 molecules of N₂.
Hence, the stoichiometric ratio between NH₃ and N₂ is 2 : 1.
Stoichiometric ratio = molar ratio
Hence, molar ratio between NH₃ and N₂ is 2 : 1. This can be written as
moles of NH₃ / moles of N₂ = 2 / 1
