Diffusion coefficients for vapors in air can be determined by measuring the rate of evaporation of a liquid from a vertical glass tube. For a tube 0.2 cm in diameter filled with n-heptane at 21°C, calculate the expected rate of decrease of the liquid level when the meniscus is 1 cm from the top based on the published diffusivity of 0.071 cm²/s. At 21°C the vapor pressure and density of n-heptane are 0.050 atm and 0.66 g/cm³, respectively. Would there be any advantage in using a larger-diameter tube?