chem help please

Question

If 6.6 L of ammonia at STP react with excess oxygen, how many grams of water are produced?

Answer 1

The balanced reaction is 4 NH₃ + 3 O₂ --> 2 N₂ + 6 H₂O. At STP, 1 mol of gas occupies 22.4 L. So (6.6 L NH₃ ) * (1 mol NH₃ / 22.4 L) * (6 mol H₂O / 4 mol NH₃ ) * ( 18.0g H₂O / 1 mol H₂O ) = 8.0 g H₂O.