A spherical rubber container of diameter \(200 \mathrm{~mm}\) and wall thickness \(1 \mathrm{~mm}\) contains a gas at a pressure of \(5 \mathrm{bar}\). The container is placed in air of pressure \(1 \mathrm{bar}\) and temperature \(20^{\circ} \mathrm{C}\). Determine the initial rate at which the pressure in the container changes if the gas is pure nitrogen. Determine the time rate of pressure change if the gas is pure oxygen. Assume air is composed exclusively of \(\mathrm{O}_{2}\) and \(\mathrm{N}_{2}\), with their partial pressures in the ratio 0.21:0.79.