Determination of diffusivity (Fig. 22B.7) the diffusivity of water vapor in nitrogen is to be determined at a pressure of 1 atm over the temperature range from 0°C to 100°C by means of the "Arnold experiment" of Example 20.1-1. It will, therefore, be necessary to use the correction factor θ_AB to the penetration model. Calculate this factor as a function of temperature. The vapor pressure of water in this range may be obtained from Fig. 22B.7 or calculated from log₁₀ P_H2O = 0.6715 + 0.030T - 0.00008T² where PH₂O is the vapor pressure in mm Hg, and T is the temperature in degrees centigrade.