Oxygen Consumption

    "An average human breathe 12 times a minute.  During each breath, 500 mL of air molecules are inhaled.  What is the oxygen consumption in lbs per day? "

(1) Find  the volume of O2 actually absorbed into the aveoli of the lung per breath.
Hint: Assume that oxygen compositions in inhaled and exhaled breaths are approximately 20 % and 15 %, respectively. Namely, only a quarter of O2  inhales are actually consumed. You may also assume that temperature of the air is 25 oC.

(2) Find  the total volume of O2  absorbed in a day.

(3) Convert the volume to mass in lbs.
Hint: a. Find mole of O2 from the volume
      b. Convert the mole to mass (in g), then to lbs.