Equilibrium Constant, Infrared Spectrum, and Thermodynamic Properties of Bromine Chloride

The equilibrium constant of 0.15 for the gaseous system 2BrCl = Br2+Cl2 has been determined by means of a mass spectrometer. The fundamental vibration frequency of BrCl was observed at 439.5 cm-1 wave numbers in the infrared spectrum. The thermodynamic properties — (F — E00), S, and Cp were calculated for one mole of gas at atmospheric pressure from 100—1000°K. From the thermodynamic properties, equilibrium constant and known standard state properties of Br2 and Cl2, the standard state properties of BrCl were computed. There was no evidence for the existence of BrCl3.