Question

How many total atoms are there in 74.5 g of carbon dioxide (CO2)? I am not sure if I did it correct I ended up getting 1.02 * 10^24 atoms? Is that correct

Answer 1

Molar mass CO₂ = 44.0 g/mol

44.0 g ----------------- 6.02x10²³ molecules
74.5 g ----------------- ??

74.5 x ( 6.02x10²³) / 44.0

= 1.019x10²⁴ molecules of CO2

Calculate the number of atoms :

CO₂ => 1 atom of Carbon  ,  2 atoms of Oxygen ( 1 + 2 = 3  atoms )

therefore:

1 molecule CO2 ---------------------- 3 atoms
1.019x10²⁴ CO2 --------------------- ?? atoms

3 x ( 1.019x10²⁴) / 1 = 

= 3.057x10²⁴ atoms of CO₂

hope this helps!