Prediction of Thermodynamic Properties of Chlorine Gas as an Environmental Pollutant

Chlorine has been known as one of the most common toxic inhalants and respiratory tract irritant. Chlorine is a yellow-green gas at room temperature, moderately water-soluble, and more than twice as heavy as air [1]. Exposure to higher concentrations of chlorine may lead to in the development of pulmonary edema, pneumonitis, respiratory failure, and death [2,3]. The aim of the present study was to investigate of thermodynamic properties of the reaction of chlorine with hydrogen to produce hydrochloric acid in gas phase as Cl2(g) + H2(g) → 2HCl(g). In this regard, we used the improved Manning-Rosen potential model for the vibrational function of diatomic molecules [4]. Some thermodynamic properties such as enthalpy, free energy, and entropy for Cl2 and HCl gases were calculated in wide range of temperature. The results obtained showed that enthalpy and free energy values increased uniformly with increasing temperature. Although the special vibrating heat increased with increasing temperature first, and then it decreased where the temperature reached to the maximum. The observed behavior is in agreement with experimental data.