Pressurized hydrogen gas is stored at 358 K in a 4.8-m-outer-diameter spherical container made of nickel. The shell of the container is 6 cm thick. The molar concentration of hydrogen in the nickel at the inner surface is determined to be 0.087 kmol/m3. The concentration of hydrogen in the nickel at the outer surface is negligible. Determine the mass flow rate of hydrogen by diffusion through the nickel container. The binary diffusion coefficient for hydrogen in the nickel at the specified temperature is 1.2 X 101 m2/s