How many atoms of hydrogen are there in 1,235 liters of hydrogen?

Conversion Factors

We will need to use the following mole conversion factors to work this problem:

  1 mole = 22.4 liters

  1 mole = 6.02 x `~10^23` atoms

Mole Conversion Calculation

The given amount is: 1,235 L `~H_2`

The calculation will take the general form:

  (Given amount)(Liter mole conversion factor)(atom mole conversion factor)

Therefore,

   1235 L x (1 mole/22.4 L) x (6.02 x `~10^23`atoms /1 mole) =

       3.319 x ~10^25 atoms `~H_2`

Notice that the first mole conversion factor is oriented such that the unit "Liters" is on the bottom. This enables us to cancel out the unit of liters.

Notice also that the second mole conversion factor is oriented such that the unit "mole" is on the bottom. This enables us to cancel out the unit of moles. 

The only unit that remains uncanceled is "atoms."