How many atoms of oxygen are present in 5 moles of CO2? (NA = 6.023 x 10^23)

1. One mole of CO2 contains 2 moles of oxygen atoms. 2. So 5 moles of CO2 contain $5 \times 2 = 10$ moles of oxygen atoms. 3. Atoms of oxygen $= 10 \times 6.023 \times 10^{23}$. 4. $= 6.023 \times 10^{24}$ atoms. Forgetting the factor of 2 (using 5 moles of O) gives $3.011 \times 10^{24}$. _Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 7 Atoms and Molecules "Solved Problems", p.108_