To calculate the mass of a substance given its moles, you need to know its molar mass. The molar mass of oxygen (O₂) is approximately 32 grams per mole.
To find the mass of 2.4 moles of O₂, you can multiply the number of moles by the molar mass:
Mass = Moles × Molar mass
Mass = 2.4 moles × 32 grams/mole
Mass = 76.8 grams
Therefore, there are approximately 76.8 grams in 2.4 moles of O₂.