Statistical–mechanical calculations of thermal properties of diatomic gases

The impact of rotational–vibrational dynamics of molecules on the molecular partition functions, law of mass action and thermodynamic functions of partially dissociated diatomic gases is discussed. A group of 11 gases, expected to have their partition functions the most sensitive to the molecular rotational–vibrational properties, is selected for rigorous and detailed studies, and the partition functions, dissociation degrees and free energies of the gases are calculated (using various models of molecular rotational–vibrational dynamics) and compared in a broad range of temperature and particle density.