If a sample of nitrogen gas (N2) contains 1.2 x 10^24 atoms of nitrogen, then about how many moles of nitrogen gas are in the sample?

5.0

1.0

2.5

3.0

The number of moles of nitrogen gas is 1.0 mole

calculation

N2 is a molecule therefore;

1 molecule of N₂ = 2 atoms of N

? molecules = 1.2 x10 ²⁴atoms

by cross multiplication

=[ (1.2 x 10²⁴ atoms x 1 molecule) / 2 atoms] = 6 x 10²³ molecules

According to Avogadro's law 1 mole = 6.02 x 10²³ molecules

? moles = 6.0 x 10²³ molecules

by cross multiplication

= [ (6.0x 10²³ molecules x 1 mole) / 6.02 x10²³ molecules] = 1.0 mole