Consider the following equation:

Question

4 NH3 (g) + 5 O2(g) 4 NO (g) + 6 H2O(g)

(a) How many liters of oxygen are required to react with 2.5 L NH3 ? Both gases are at STP.

Answer 1

When gases are involved one may use a short cut in which L are used as if they were mols.
4 NH3 (g) + 5 O2(g) 4 NO (g) + 6 H2O(g)

Therefore, 2.5 L x (5 mols O2/4 mols NH3) = ? L O2