MHT CET Medical202624 April 2026Morning ShiftChemistrySome Basic Concepts of ChemistryActual
Find the mass of lime obtained by heating 500 g of 90 % pure lime stone. [Molar masses Ca =40 g/mol, O =16 g/mol & C =12 g/mol]
Options
- A252 g
- B280 g
- C265 g
- D230 g
Correct answer
A. 252 g
Step-by-step solution
Mass of pure CaCO ₃ in the sample is 500 90 100 = 450 g. Molar mass of CaCO ₃ = 40 + 12 + 3 16 = 100 g/mol. Moles of CaCO ₃ = 450 100 = 4.5 mol. The decomposition reaction is: CaCO ₃ CaO + CO ₂ From the stoichiometry, 1 mole of CaCO ₃ produces 1 mole of CaO (lime). Moles of CaO produced = 4.5 mol. Molar mass of CaO = 40 + 16 = 56 g/mol. Mass of lime obtained = 4.5 56 = 252 g. Answer: 252 g