Consider the diffusion of species A (gas) into a solid medium of diffusion B (stationary). The initial molar concentration of species A within the diffusion medium is considered negligible whereas the partial pressure of A in the gaseous phase is known p_a. Furthermore, the molar flux of species A at a distance d, below the surface of medium B cannot exceed a safety constraint value of N kmol/s*m2. Calculate the time required for the above safety constraint to be reached, assuming that both the binary diffusion coefficient as well as the solubility of A in B have known constant values.

Problem 1 [50pts): Consider the diffusion of species A (gas) into a solid medium of diffusion B (stationary). The initial molar concentration of species A within the diffusion medium is considered negligible whereas the partial pressure of A in the gaseous phase is known P Furthermore, the molar flux of species A at a distance d below the surface of medium B can not exceed a safety constraint value of N kmol/s-m. Calculate the time required for the above safety constraint to be reached, assuming that both the binary diffusion coefficient as well as the solubility of A in B have known constant values