Question

Hi again, I actually asked this same question while time ago, but had never got an answer for it, if anyone can help me, it would be most grateful. If possible, please leave some short explanation in your answer. Thanks
1. Suppose that the equilibrium
4NH3(g) + 3O2(g) = 2N2(g) + 6H2O(g)
were established by adding 0.30 mol NH3 and 0.40 mol oxygen to a 5.0 L container. If "y" moles of water are present at equilibrium, then what would the concentration of oxygen be...

A. 0.40 - 0.50 y

B. 0.08 - 0.10 y

C. 0.30 - 0.50 y

D. 0.06 - 0.13 y

E. 0.40 - 3y/2