Question: what is the limiting reactant of n2(g)+3h2(g)→2nh3(g)?
Answer: Number of moles of N2 = 100 moles/1 = 100 mole. To react with 100 moles of N2, 300 moles of H2 should be present. But only 100 moles are present. Therefore, H2 is the limiting reactant.