No abstract

No abstract

In this study, the improved Tietz potential was used to describe the internal vibration of diatomic molecules. By employing the expression for upper bound vibrational quantum number and canonical partition function of the system, equation for the prediction of constant pressure (isobaric) molar heat capacity of diatomic molecules was derived. The analytical model was used to predict the isobaric molar heat capacity of the ground state CO, BBr, HBr, HI, P2, KBr, Br2, PBr, SiO, and Cl2 molecules. The upper bound vibrational quantum number obtained for the molecules are 85, 100, 21, 21, 115, 301, 89, 157, 110, and 67. The calculated average absolute deviations are 2.3462%, 1.1342%, 2.3350%, 1.9078%, 0.7268%, 2.4041%, 1.7849%, 1.8989%, 2.5209%, and 2.1523% from experimental data. The results obtained are in good agreement with available literature data on gaseous molecules.

In this study, the improved Scarf II oscillator was used to model the internal vibration of a diatomic molecule. By employing the equation of energy levels of the oscillator, the canonical partition function was obtained and used to derive analytical expressions for the prediction of molar entropy, enthalpy and isobaric heat capacity of substances. The thermodynamic models were used to analyze the thermodynamic properties of some diatomic molecules including BBr, PN, PO, and PCl. The average absolute deviation from experimental data was used to affirm the suitability of the models. The expression for the reduced molar enthalpy yielded an average absolute deviation of 1.0945%, 1.6959%, 1.0013%, and 1.0945% for the molecules. Average deviations of 1.3053%, 1.5024%, 1.3838%, and 0.7490% were also obtained using the heat capacity model. These results are in good agreement with the existing literature data on selected diatomic molecules.

Abstract