Ok so say you have 50. liters and your turning that into molecules how would you do and what would the answer be? Any answer is welcome as long as its logic.

-Thank you

50 liters of what?

If you are talking about a liquid, you will need to know the density of the liquid (how much does 5 liters weigh), and the molecular weight of the liquid (grams per mole) - then you can convert like this:

Volume(liters) x grams/liter X 1/(grams/mole) x Avogadro's number (molecules/mole) = molecules.

If it's a gas you're talking about, then you can use the ideal gas law: PV=nRT. You will need to know the gas's pressure (P) and temperature (T) - then the number of moles is n = RT/PV. Once you have a value for n, you can multiply by Avogadro's number to get the number of molecules.