Based on the molecular argument in Section 15.1, we expect that diffusivities will increase with increasing temperature. This is indeed the case. Fortunately, in most cases the temperature dependence can be quite accurately predicted. Ideally, the diffusivity would not depend on concentration. For gases this is approximately true. Typical diffusivity data for gases are given in Table 15-1. At pressures below about 70 atm and at constant temperature, the product [ptot DAB] is constant for each gas pair, and DAB is independent of concentration.
Please do not consider the tables as an opportunity for a reading break. Instead of skipping Table 15-1, study the numbers and try to find patterns. Obviously, D