Hydrogen gas can be purified by passing atomic hydrogen through a thin sheet of palladium at 700C in a palladium diffusion cell. If the impure hydrogen gas is maintained at 1 atm on one side of a 1 mm thick Pa sheet (A=1 cm2), and the pressure on the purified side is maintained at 0.1 atm by pumping, what is the mass of the hydrogen purified in 1 hr? The concentration of H2 at 1 atm is 9x10-3 g/cm3 and the D(H) in Pa is 1.2x10-6 cm2/sec.