Question

Ammonia, NH3, is widely used as a fertilizer and in many household cleaners. How many moles of ammonia are produced when 6 mol of hydrogen gas react with an excess of nitrogen gas?

Answer 1

N2 + 3H2 ==> 2NH3
The equation tell you that you get 2 mols NH3 for every 3 mols H2 so if you have 6 mols H2 gas (instead of 3) wouldn't you think you would get 4 mols NH3? Or in good math terms.
6 mols H2 gas x (2 mols NH3/3 mol H2) = 4 mols NH3.