Verify by calculating that 5 moles of CO2 and 5 moles of H2O do not have the same mass. (b) 240 g of calcium and 240 g of magnesium elements have a mole ratio of 3 : 5.

(a) CO2 has molar mass = 44 g mol^-1

5 moles of Co₂ have molar mass = 44 x 5 = 220 g

H₂0 has molar mass = 18 g mol^-1

5 moles of H₂O have mass = 18 × 5 g = 90 g

(b) Number of moles in 240 g Ca metal = 240/40 = 6

Number of moles in 240 g of Mg metal = 240/24 = 10

Ratio is 6 : 10

Or, 3 : 5