You detected O2 storage tank leaked a gas at a constant rate through a 1.6 mm-thick stagnant layer of air. Conditions are such that at one boundary of the stagnant layer, the gas contains 65% 02 by volume, whereas its concentration at the other boundary can be considered negligible. The total pressure and the temperature are 1 atm and 25 C, respectively. Determine the rate of diffusion of O2 through the layer of air.