(into the 0.9mm thick cloth slab), the sweater was soaked in the Tide-to-Go solution (ethanol). Continuous scraping with the pen tip gives rise to a mass transfer coefficient on the liquid side of km=0.0002m/s The amount of time needed to clean a piece of clothing is dependent on how fast the ethanol solvent (A) can penetrate the cloth. The diffusion coefficient of A in the swollen cellulose fibers is DAB=0.077cm2/s. a) Calculate the Biot number and explain what the result means. b) When has 99% of the stain been removed (i.e. cloth is 99% saturated with solvent)? (into the 0.9mm thick cloth slab), the sweater was soaked in the Tide-to-Go solution (ethanol). Continuous scraping with the pen tip gives rise to a mass transfer coefficient on the liquid side of km=0.0002m/s The amount of time needed to clean a piece of clothing is dependent on how fast the ethanol solvent (A) can penetrate the cloth. The diffusion coefficient of A in the swollen cellulose fibers is DAB=0.077cm2/s. a) Calculate the Biot number and explain what the result means. b) When has 99% of the stain been removed (i.e. cloth is 99% saturated with solvent)