Gaseous hydrogen at 10 bars and 27C is stored in a 100-mm-diameter spherical tank having a steel wall 2mm thick. THe molar concentration of hydrogen in the steel is 1.50kmol/m^3 at the inner surface and negligible at the outer surface, while the diffusion coefficient of hydrogen in stell is appoximately 0.3 x 10^-12 m^2/s. What is the initial rate of mass loss of hydrogen by diffusion through the tank wall? What is the initial rate of pressure drop within the tank?