A cylindrical graphite (pure carbon) rod of length 25 cm and initial diameter of 2 cm is inserted into a flowing air stream at 100 K and 2 atm total pressure. The flowing gas creates a stagnant gas boundary layer of 5 mm thickness around the external surface of the rod. How long it will take for the rod to disappear? Partial pressures are, PoA1= 0.5 atm and PoA2= 0 atm. The density of solid graphite is 2.25 g/cm3. Molecular weight of graphite is 12 g/mol. Assume pseudo-steady state and equimolar counter diffusion.