Question

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

Answer 1

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

Answer 2

The answer to your question is B. 2.5