1. A dry food product is contained in a 1 cm x 4 cm x 3 cm box using a polymer film to protect the oxygen sensitivity of the product. The concentration gradient across the film is defined by the oxygen concentration in air (0.01164 kg/m3) and 0.244 kg/m3 within the package. The oxygen diffusivity for the polymer film is 3 x 10-16 m2/s. Estimate a- the allowable flux of oxygen into the package (in kg O2/s), and b- the film thickness needed, to ensure a product shelf life of 10 months. The shelf life of the product is established as the time when oxidation reactions within the product have used 0.5 mol of oxygen.