Oxygen at 25?C and pressure of 2 bar is flowing through a rubber pipe of inside diameter 25 mm and wall thickness 2.5 mm. The diffusivity of O2 through rubber is 0.21 x 10-9 m2/s and the solubility of O2 in rubber is 3.12x10-3 kg-mole/m^-3 bar . Find the loss of O2 by diffusion per metre length of pipe.