According to the balanced chemical equation, the stoichiometric ratio of NH3 to O2 is 4:3. This means that for every 4 moles of NH3, we need 3 moles of O2 to fully react.
To determine how many moles of O2 are needed to fully react 11 moles of NH3, we can set up a proportion:
4 moles NH3 : 3 moles O2 = 11 moles NH3 : x moles O2
Solving for x, we get:
x = (11 moles NH3 * 3 moles O2) / 4 moles NH3
x = 8.25 moles O2
Therefore, 8.25 moles of O2 are needed to fully react 11 moles of NH3.
So the correct answer is: 8.25 mol O2