A person at rest inhalesof air with each breath at a pressure of and a temperature of.The inhaled air is oxygen. (a) How many oxygen molecules does this person inhale with each breath? (b) Suppose this person is now resting at an elevation of but the temperature is still. Assuming that the oxygen percentage and volume per inhalation are the same as stated above, how many oxygen molecules does this person now inhale with each breath? (c) Given that the body still requires the same number of oxygen molecules per second as at sea level to maintain its functions, explain why some people report “shortness of breath” at high elevations.

The air is behaving as an Ideal gas Therefore use Ideal Gas Equation

where P= pressure of air, V=volume of air ,n=number of moles ,T=absolute temperature

(a)

The person inhales volume of oxygen given as

The breath are taken at the pressure of

Thetemperatureis given

The Boltzman constant is given

The percentage of oxygen in air is given

Number of inhaled molecules is given

Therefore , number of inhaled molecules by the person with each breath is .

(b)

The person is at height .

The molar mass of the air is

The pressure at sea level

Solve for pressure at altitude (h)

Solve for Number of inhaled moleclues

Therefore , at elevation of the person inhales number of oxygen molecules.

The bodyrequires thesame number of oxygen molecules per second to maintain its function at the high elevation as at the sea level and at the highelevation the numberof oxygenmoleculesper breath are less as compared to molecules at sea level so the person must increase the breath rate toinhalemore number of molecules .

Therefore , A person must increase the breath rate to match the required amount of oxygen .