THE INFRARED-SPECTRUM AND VAPOR-PRESSURE OF LEAD DIIODIDE

The infrared spectrum of lead diiodide vapour was measured at 775 K an d values were assigned to the fundamental vibrational frequencies. The results were used with other known molecular parameters to calculate the thermal functions of the gas. The vapour pressure over the solid w as measured by the Knudsen effusion technique in the temperature range 580 to 621 K. The results were subjected to a second-law and third-la w analysis and the enthalpy and entropy of sublimation were calculated .