A spherical ball of solid, nonporous naphthalene, a ‘‘moth ball’’, is suspended in still air. The naphthalene ball slowly sublimes, releasing the naphthalene into the surrounding air by molecular diffusion-limited process. Estimate the time required to reduce the diameter from 2 to 0.5 cm when the surrounding air is at 347Kand 1.013 × 105 Pa. Naphthalene has a molecular weight of 128 g/mol, a solid density of 1.145 g/cm3, a diffusivity in air of 8.19 × 10−6 m2/s, and exerts a vapor pressure of 5 Torr (666 Pa) at 347 K.