How many grams of HCl are needed to react with 10 g of CaCO₃ to produce 4.4 g of CO₂? (Molar masses: CaCO₃ = 100 g/mol,
Reaction: CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O. Moles of CO₂ = 4.4/44 = 0.1 mol; needs 0.1 mol CaCO₃ (10 g). 0.1 mol CaCO₃ requires 0.2 mol HCl = 0.2 × 36.5 = 7.3 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Reactions in Solutions and Mass Percentage and Numericals
