Study of the Vapors of Liquid Lead and Bismuth

Abstract

The total vapor pressure and mass loss per unit time of lead and bismuth vapor were determined by the torsion—Knudsen-effusion—recoil method. The average molecular weight of bismuth was determined as a function of temperature assuming the presence of a monomer and dimer species. The bismuth vapor composition is approximately 65% Bi2 and 35% Bi in the temperature range of investigation, 850° to 950°K. The average molecular weight of bismuth vapor decreased with increasing temperature. Vapors of lead were found to be monatomic. In addition, the heats of dissociation and vaporization have been determined.