- Calculate the molecular mass of CaCO3 at mass Ca=40u,C=12u,O=16u
- Verify by calculating that
- 5 moles of CO2 and 5 moles of H2O do have the same mass.
- 240g of calcium and 240g of magnisium element have a mole ratio of 5:3.at mass H=1u ,Ca=40u,Mg=24u
1. The molecular mass of CaCO3 is (40u +12u + 16× 3 u)
Hence the molecular mass is 100 u.
2. Mass of 1 mole of water is 18 g, Hence the mass of 5 mole of water is 90 g
Mass of 1 mole of CO2 is 44 g ,
∴ the mass of 5 moles of CO2 is 220 g
Hence the mass of 5 moles of water ≠ mass of 5 moles of carbon dioxide.
3. Molar mass of calcium is 40 g per mole and the molar mass of magnesium is 24 g per moles.
number of moles of calcium = 240/ 40
= 6 moles
number of moles of magnesium = 240/ 24
= 10 moles
Hence the mole ratio of Mg and calcium is 10:6 i.e. 5:3