Specify the thickness of a capsule (spherical, inner radius =2mm ), to assure a shelf-life of 6 months (182 days), to meet the criterion that the active ingredient A cannot lose more than 10% of its initial amount. The diffusion coefficient of A in the capsule material is 31015m2/s. The equilibrium constant is b= 1. Assume the concentration remains constant inside the capsule. The Al is infinitely diluted outside the capsule. Solve for the capsule thickness