Limiting and Excess Reactants

N₂ is the limiting reactant and is completely consumed.

HCl is limiting. CaCl₂ formed = 0.5 mol. Mass = 55.5 g.

The limiting reactant determines the maximum product obtainable.

Stoichiometric mixture. Titanium formed = 1 mol = 48 g.

Carbon is limiting. CH₄ = 1.5 mol. Mass = 24 g.

The limiting reactant determines how much of the excess reactant is used.

Stoichiometric mixture. H₂ produced = 0.3 mol. Volume = 6.72 dm³.

Stoichiometric mixture. Na₂CO₃ = 1 mol. Mass = 106 g.

AgNO₃ = 0.2 mol and Cu = 0.1 mol. Stoichiometric mixture. Ag formed = 0.2 mol = 21.6 g.

O₂ is limiting. P₂O₅ formed = 0.8 mol.

An inexpensive reactant is often used in excess so that the valuable reactant is completely consumed.

One mole X requires 3 mol Y. Only 2 mol Y are available.

Al = 0.667 mol and is limiting. H₂ produced = 1 mol. Volume = 22.4 dm³.

SO₂ is limiting. SO₃ formed = 2 mol. Mass = 160 g.

Both react stoichiometrically. CO₂ formed = 0.5 mol. Volume = 11.2 dm³.

Fe = 0.5 mol (limiting). FeS formed = 0.5 mol. Mass = 44 g.

Stoichiometric mixture. P₄O₁₀ = 0.5 mol. Mass = 142 g.

10 mol A require 20 mol B. Only 10 mol B are available, so B is limiting.

BaCl₂ is limiting. BaSO₄ formed = 0.3 mol. Mass = 69.9 g.