18.1g of ammonia and 90.4g of copper(II) oxide are used in the reaction 2NH3+3CuO=N2+3Cu+3H3O.What is the limiting reactant? How many grams of nitrogen will be formed?

Answer 1

mols NH3 = grams/molar mass = estimated 1.0
mols CuO = g/molar mass = estimated 1.1

Convert mols each to mols product. N2 is the easiest.
1 mol NH3 x (1 mol N2/2 mol NH3) = 1 x 1/2 = estimated 1/2 mol N2.

1.1 mol CuO x (1 mol N2/3 mol CuO) = estimated 1.1 x 1/3 = about 0.4
So CuO is the limiting reagent because the smaller amount will be formed.

g N2 = mols N2 x molar mass N2.