Question

II The small capillaries in the lungs are in close contact with the alveoli. A red blood cell takes up oxygen during the 0.5s that it squeezes through a capillary at the surface of an alveolus. What is the diffusion time for oxygen across the 1-um thick membrane separating air from blood? Assume that the diffusion coefficient for oxygen in tissue is .2x10^-11m^2/s Give your answer to 1 significant figure.

Answer 1

The diffusion time for oxygen across the 1-um thick membrane separating air from blood is approximately 5,000 seconds.

Step-by-step explanation:

The diffusion time for oxygen across the 1-um thick membrane separating air from blood can be calculated using Fick's Law of diffusion. According to Fick's Law, the diffusion time (t) is equal to the thickness of the membrane (d) squared, divided by the diffusion coefficient (D). In this case, the diffusion time for oxygen across the 1-um thick membrane would be:

t = (d^2) / D

Given that the thickness of the membrane (d) is 1 um and the diffusion coefficient (D) for oxygen in tissue is 0.2x10^-11 m^2/s, we can substitute these values into the equation:

t = (1 um)^2 / (0.2x10^-11 m^2/s)

Converting the thickness of the membrane to meters:

t = (1x10^-6 m)^2 / (0.2x10^-11 m^2/s)

Simplifying the equation:

t = 5x10^3 s

Therefore, the diffusion time for oxygen across the 1-um thick membrane separating air from blood is approximately 5,000 seconds.