Thermo Gases>Ideal Gas Law Practice Test

A 500 mL spirometer bag is filled with dry air at body temperature (37 C) and 1 atm. Which of the following is closest to the value of the number of moles of gas in the bag?

At 37 C and 1 atm, a patient's lungs contain 3.0 L of air in which oxygen is 21% by mole. Which of the following is closest to the value of the moles of O2 present?