4.9. A piece of porous glass tubing is used as a diffusion cell to measure the diffusion coefficient of an air-gas mixture. The inside diameter and outside diameter of the cell are I mm and 4mm...

Extracted text: 4.9. A piece of porous glass tubing is used as a diffusion cell to measure the diffusion coefficient of an air-gas mixture. The inside diameter and outside diameter of the cell are I mm and 4mm respectively. It was found that with a difference in mole fraction of 10 percent at 25°C and 1 atm pressure, the molar flow rate was 4.0 x 10 mol s m's. per centimeter of length. Find the diffusion coefficient in