### In Class We Found The Oxygen Permeability Of The Walls Of The Alveolus To Be 1 8

In class we found the oxygen permeability of the walls of the alveolus to be 1.88 X 10-5 cm/s. This result assumed that the number of oxygen molecules per volume of air was 5.63 X 1018 molecules per cubic centimeter and that the concentration of oxygen in the blood was essentially zero. With these same assumptions at what rate would the volume of the alveolus be decreasing if carbon dioxide were not diffusing in? Let the starting radius of the inflated alveolus be 0.15 um at 37 and 1 atmospheric pressure. Also assume that air is an ideal gas, that the temperature and pressure in the alveolus remains constant and the alveolus is a sphere. The answer will be exact.

a)1.27 X 10-14 cm3/s

b)0.33 X 10-14 cm3/s

c)2.85 X 10-14 cm3/s

d)9.71 X 10-14 cm3/s

e)7.04 X 10-14 cm3/s