If you have 2.2 x 10^24 molecules of o2 at stp how many liters of o2 do you have

According to Avogadro law the volume and moles of a gas is directly proportional at constant pressure and temperature.

Number of moles is therefore number of molecules/Avogadro constant (6.02 x10^23)

(2.2 x10^24) / (6.02 x10^23) = 3.654moles

Every moles of an ideal gas occupy 22.4L at S. T. P

therefore volume is

3.654 x22.4L=81.85L