A50 m3 brewing vessel at the end of a batch process to make beer, has an atmosphere of 50mol% air : 50 mol% carbon dioxide. the vessel is vented to the atmosphere via a duct 3 m long. the duct is 2 m in diameter at the top of the vessel reducing to 30 cm on the roof. the vessel has a pressure of one atmosphere and temperature of 25 ºc. given that the diffusivity of the carbon dioxide is 0.164 ×104 m2s -1 calculate 1) the rate of diffusion of the co2 out of the vessel in mols/hr 2) the rate of of air diffusing into the vessel in kg/hr]