find the limiting reagent for each set of reactants 4NH3(g) +3O2(g) = 2N2(g) + 6H2O(l) if you have 7.00 mol NH3 + 5.00 mol O2

Answer 1

Use the coefficients to convert mols of each to mols of any product; e.g. N2.
7 mols NH3 x (2 mols N2/4 mols NH3) = 7/2 = 3.5 mols N2.
5 mol O2 x (2 mols N2/3 mols O2) = 10/3 = 3.33 mol N2.
So the smallest amount of N2 will form which makes O2 the limiting reagent. That
s the long way.

Short way. 7 mol NH3 will require 7*3/4 mol O2 or 21/4 = 5.25 but you don't have tht much O2 so O2 must be the LR.