Example-1.9) Unsteady-State Diffusion in Solid Cotton seeds which contair 18kg oil per m3 of solid and are pressed in the form of slabs with 12mm8mm3mm dimensions, are immersed in hexane to extract the oil Calculate their oil content after 1 hour of contact. The solution is well mixed so that resistance to mass transfer is only in the solid phase. Molecular diffusivity of oil in solid at the operating conditions is 4.11010m2/s