Studies in the Lead Chloride--Lead Bromide System

Abstract

A study of the lower explosion limit of the nitrous oxide-hydrogen system reveals the existence of a minimum in the pressure versus temperature curve for mixtures of any fixed compositions. The addition of molecular oxygen poisons the explosive reaction, and this suggests that the minimum is due to the poisoning of the reaction by oxygen from the thermal decomposition of nitrous oxide. In view of the results of Melville's study of the slow reaction, the mechanism of poisoning must be H + Os + -» H02 + M.After passing through the minimum, the explosion limit does not increase indefinitely as the temperature is raised. Above 900°it decreases again in a vycor vessel, but could not be observed to decrease in quartz vessels of the size employed. In vycor above 900°, the explosion is not strongly affected by added oxygen and this insensitivity would be expected from the interpretation of the low .temperature results.Aberdeen Proving Ground, Md.

Effects of Chemical Disorder on Localized States in Amorphous PbCl2(1-x)Br2x Studied by UV Absorption Measurements

“…Lead chloride and lead bromide are known to show complete mutual solid solubility [16]. For the preparation of the PbC12(1 -s)Br2r solid solutions, nominal amounts of PbCl2 and PbBrz in powder form were mixed together and melted at 600 "C for 1 h in a silicatube container purged with Ar gas.…”

Physical and chemical characteristics of particulates in spark ignition engine exhaust

“…Vapor pressure data for PbCU and PbBr2 were taken from Weast and Selby (1966). For PbCIBr the vapor pressures were estimated by using values of the equlibrium constant for the reaction PbCU + PbBr2 -1-2PbClBr (Bloom and Hastie, 1967), and the melting point of PbCIBr, as reported by Calingaert et al (1949). The values of P, pg, and Mg were taken to be 760 mm Hg, 0.012 g/cm3 and 28.17 g/g-mol, respectively.…”

Standard x-ray diffraction powder patterns :

“…Orthorhombic, Pnam (62) , Z = 2; BaCl2 and PbCl2 form a complete solid solution series [Calingaert et al . , 1949].…”

“…Orthorhombic, Pnam (62), Z=4, isostructural with BaCl2 . There is a complete solid solution series between PbBr2 and PbCl2 [Calingaert et al,1949] The structure of PbCl2 was deteirmined by Brakken and Harang [1928] NBS lattice constants: a = 7.801(1)A…”