Question

What is the limiting reactant when 6.8 moles of iron react with 8.9 moles of oxygen gas?

Answer 1

Unbalanced equation: Fe + O2 → Fe2O3

Answer 2

The balanced equation would be:
4Fe+3O2--> 2Fe2O3

Answer 3

now that you have the correct coefficients use stoichiometry to go from the initial moles to the product.

Answer 4

for 4 mole of Fe 3 mole of O2 is needed
for6.8 mole of Fe =3*6.8/4=2.85 mole of O required
but u have 8.9 moles hence it is in excess
Fe is its limiting reactant