Water in an open dish exposed to dry air at 25°C vaporizes at a constant rate of 0.07g/h-cm². If the water surface is at the wet bulb temperature of 11.0°C, calculate the effective gas film thickness. Diffusion volume of water, (v) = 13.1 Diffusion volume of air, (Σ = 19.7 a) 0.21 cm b) 0.12 cm c) 0.32 cm d) 0.19 cm