3. How many molecules of carbon dioxide are contained in a 1.65 mole sample of carbon
dioxide?

9.93 x 10^23 atoms

Explanation:

Based on Avogadro's law:

1 mole of any substance has 6.02 x 10^23 atoms

So, 1 mole of carbon dioxide = 6.02 x 10^23 atoms

1.65 moles = Z atoms

To get the value of Z, cross multiply:

Z atoms x 1mole = (6.02 x 10^23 x 1.65)

Z = 9.93 x 10^23 atoms

Thus, there are 9.93 x 10^23 atoms of carbon dioxide.