Thermal Analysis of the System PbBr2–PbO

Abstract

A thermal analysis of the system PbBr₂–PbO proved the existence of four compounds intermediate between PbBr₂ and PbO, namely PbBr₂·PbO, PbBr₂·2PbO, PbBr₂·3PbO, and PbBr₂·7PbO. The compound PbBr₂·PbO was unstable above 497°C whereas the others were stable at their melting points. Pure PbBr₂·PbO·H₂O (or Pb(OH)Br) was prepared and was found to decompose into PbBr₂·PbO at temperatures above 150°C. This work offers an explanation for the discrepancies among data reported in the literature for the melting point of lead bromide.