If there is 5.67 x 1024 molecules of CO2, what is the mass?

1 mole of CO₂ contains 6.022 × 10²³ CO₂ molecules.
No. of moles of CO₂ = (5.67 × 10²⁴) / (6.022 × 10²³ /mol) = 9.42 mol

Molar mass of CO₂ = (12.0 + 16.0×2) g/mol = 44.0 g/mol
Mass of CO₂ = (44.0 g/mol) × (9.42 mol) = 414 g (to 3 sig. fig.)