If a sample of nitrogen gas (N2) contains 3.0 x 10^24 atoms of nitrogen, then about how many moles of nitrogen gas are in the sample?

A. 5.0

B. 2.5

C. 3.0

D. 1.0

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 do as follows:

3.0 x 10^24 atoms N2 (1 mol / 6.022 x 10^23 atoms) = 4.98 moles or 5.0 moles of N2