Which of the following is greater?

Question

a)the partial pressure of carbon dioxide in expired air

b)the partial pressure of carbon dioxide in the alveoli

c) neither would be greater

Answer 1

Answer: a

There is more carbon dioxide in expired air.

The mole fraction of carbon dioxide can be expressed as the partial pressure / total pressure.  This means that the partial pressure of the gas component would be higher where it is more concentrated.