How many grams of nitrogen monoxide are present?

Question

When 36.3 L ammonia and 40.0 L oxygen gas at STP burn, nitrogen monoxide and water are produced. After the products return to STP, how many grams of nitrogen monoxide are present?
g
NH3(g) + O2(g) NO(g) + H2O(l) [unbalanced]

Answer 1

2NH3(g) + 5O2 ===> 2NO + 3H2O

36.3LNH3 x 1molNH3/22.4LNH3 = 1.62 mole NH3

40.0LO2 x 1molO2/22.4LO2 = 1.78 mole O2

1.62molN2 x 5molO2/2molNH3 = 4.05 mole O2.

You don't have 4.05 moles O2, so O2 is the limiting reagent: It will run out first. Returning then to oxygen:

1.78molO2 x 2molNO/5molO2 = 714 mole NO