For a skydiver jumping out of a plane at an altitude of 1 km, what would be the
concentration of oxygen in his (or her) blood knowing that air pressure at 1 km drops to
89,874 Pa? Assume ideal behavior of gases, normal breathing, 25 °C and constant air
composition. Hint: Recall Amagat’s law of partial volumes in an ideal gas mixture
Air on Earth is roughly 80% nitrogen and 20% oxygen by volume. At sea level, where
atmospheric pressure is 101,325 Pa (or 1 atm), the concentration of oxygen in human blood is
2.6 x 10-4 mol/L at 25 °C.