Potential functions and parameters for Ne-N-2 and Ar-H-2 gas mixtures

The thermal diffusion factor, alpha(T), has been measured as a function of temperature and composition for the gas mixtures Ne-N-2 and Ar-H-2 using the two-bulb method. The measurements covered the temperature range from about 325 to about 825 K and the composition range from 15% to 85% of the lighter component. The data have been analyzed according to the (m-6-8) and LJ(12-6) potential models where the intermolecular forces and the potential functions were determined for the two studied systems. The (m-6-8) parameters obtained were used to calculate the binary diffusion coefficients and these were compared with recent diffusion data. It has been found that the present (m-6-8) potential functions for the AU-H-2 system predict very well both of the thermal diffusion and the recent diffusion data with percentage deviation not exceeding 3% and the diffusion data of the Ne-N-2 system with maximum deviation of about 1%. However, both the symmetric LJ(12-6) and (m-6-8) potentials failed to explain the thermal diffusion data for the Ne-N-2 system. A conclusion has been made for this state of affairs.