Calculate the number of moles of Cl atoms in 1.81*10^24 formula units of magnesium chloride, MgCl2.

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles. We calculate as follows:

1.81*10^24 formula units MgCl2 (1 mol / 6.022x10^23 formula units) (2 mol Cl / 1 mol MgCl2) = 6.01 mol Cl atoms