Example: An open cylindrical tank is filled to within ( 2ft) of the top with pure methanol. The tank is tapered, as shown in the figure. The air within the tank is stationary but circulated adequately above the tank to assure a negligible concentration of methanol at this point. The tank and air space are at 77F and 1atm. And the diffusivity of methanol in the air is 0.62ft2/hr at 77F. Calculate the loss of methanol from the tank at a steady state. Given the vapour pressure of methanol at 77F is 13.5 mmHg