a. Number of moles = Given mass / molar mass Molar mass of oxygen = 32g/mol Number of moles in 22g of oxygen = 22/ 32 = 0.687 moles Therefore, 22g of oxygen contains 0.687 moles. b. Number of moles = Given mass / molar mass Molar mass of carbon dioxide = 44 g/mol Number of moles in 12 gm of carbon dioxide = 12 / 44 = 0.272 moles Therefore, 12gm of Carbondioxide contains 0.272moles.