# How many atoms are in 8.00 mol of CO_2 molecules?

Nov 11, 2016

$1.45 \cdot {10}^{25} \text{atoms}$

#### Explanation:

The idea here is that each molecule of carbon dioxide is made up of $3$ atoms

• one atom of carbon, $1 \times \text{C}$
• two atoms of oxygen, $2 \times \text{O}$

This means that each mole of carbon dioxide will contain $3$ moles of atoms.

• one mole of carbon atoms, $1 \times \text{C}$
• two moles of oxygen atoms, $2 \times \text{O}$

This, of course, implies that $8.00$ moles of carbon dioxide molecules will contain

8.00 color(red)(cancel(color(black)("moles CO"_2))) * "3 moles atoms"/(1color(red)(cancel(color(black)("mole CO"_2)))) = "24.0 moles atoms"

Now all you have to do is convert the number of moles to number of atoms by using Avogadro's constant

24.0 color(red)(cancel(color(black)("moles"))) * overbrace((6.022 * 10^(23)"atoms")/(1color(red)(cancel(color(black)("mole")))))^(color(blue)("Avogadro's constant")) = color(green)(bar(ul(|color(white)(a/a)color(black)(1.45 * 10^(25)"atoms")color(white)(a/a)|)))

The answer is rounded to three sig figs.