Practice question
Question
What is the mass of CaCO₃ required to react with 50 mL of 2 M HCl? (Molar mass: CaCO₃ = 100 g/mol)
Explanation
Reaction: CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O. Moles of HCl = 2 × 0.05 = 0.1 mol. 0.1 mol HCl needs 0.05 mol CaCO₃ = 0.05 × 100 = 5 g.