In a reaction A + B₂ → AB₂, identify the limiting reagent, if any, in the following reaction mixtures: (i) 300 atoms of A + 200 molecules of B₂ (ii) 2 mol A + 3 mol B₂ (iii) 100 atoms of A + 100 molecules of B₂ (iv) 5 mol A + 2.5 mol B₂ (v) 2.5 mol A + 5 mol B₂

(i) 200 molecules of B₂ will react with 200 atoms of A and 100 atoms of A will remain unreacted. Hence, B₂ is the limiting reagent (ii) 2 moles of A will react with 2 moles of B₂ and 1 mole of B₂ will remain unreacted. Thus, A is the limiting reagent (iii) 100 atoms of A will react with 100 molecules of B₂. Thus, both reagents are present in stoichiometric amounts (iv) 2.5 mole of B₂ will react with 2.5 mole of A and 2.5 mole of A will remain unreacted. Hence, B₂ is the limiting reagent (v) 2.5 moles of A will react with 2.5 moles of B₂ and 2.5 moles of B₂ will remain unreacted. Thus, A is the limiting reagent.