Oxygen diffuses from the surface of insects to the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has cross-sectional area of 2 *10^-9 m2. Assuming the concentration of oxygen inside is half what it is outside in the atmosphere.
a) Find the concentration of oxygen in the air (assume 21% is oxygen) at 20 degrees C.
b) Calculate the diffusion rate J. Assume the diffusion constant is 1×10?5m2/s.
c) Estimate the average time for a molecule to diffuse in.