MCQs

Zn = 0.1 mol, HCl = 0.2 mol. Stoichiometric mixture. H₂ = 0.1 mol. Volume = 0.1 × 22.4 = 2.24 dm³.

Al = 0.5 mol, S = 0.5 mol. Sulphur is limiting. Al₂S₃ formed = 0.5/3 = 0.1667 mol. Mass = 0.1667 × 150 = 25 g.

5 mol Al requires 3.75 mol O₂. Since 4 mol O₂ are available, oxygen is in excess. Aluminium is limiting.

Moles of N₂ = 56/28 = 2 mol. Moles of H₂ = 12/2 = 6 mol. The mixture is stoichiometric. NH₃ formed = 4 mol. Mass = 4 × 17 = 68 g.

The reactants are in the exact stoichiometric ratio. Four moles NH₃ = 68 g are produced.

O₂ is limiting. Four moles CO₂ are formed and 1 mol CO remains.

The excess reactant remains after the limiting reactant is exhausted.

O₂ is limiting. One mole NO (30 g) is formed.

0.1 mol NaOH is insufficient to react completely with 0.1 mol H₂SO₄.

Stoichiometric reaction produces 4 mol CO₂ = 89.6 dm³.

A is limiting. Product formed = (2/3) × 3 = 2 mol.

Industries optimize limiting reactants to maximize efficiency.

Stoichiometric mixture produces 3 mol S = 96 g.

Mg is limiting. Two moles Mg produce 2 mol MgO = 80 g.

The limiting reactant determines the theoretical yield.

O₂ limits the reaction. Only 2 mol P₄ react, leaving 2 mol P₄.

The reactants are present in the exact stoichiometric ratio.

It is the reactant consumed first, stopping the reaction.

CaCO₃ = 0.1 mol, HCl = 0.274 mol. Since only 0.2 mol HCl is required, CaCO₃ is limiting.