Abstract
The vapor pressure of rhenium was measured by the Langmuir method in the temperature range 2350-3050 °K using a vacuum microbalance. The least squares line through the four series of data points is 4.5756 log P(atm) = 32.26 - 180700/T. Least squares lines for each of the four series yield heats and entropies of sublimation higher than the corresponding third law values. The vapor pressure equation based on the average heat and entropy is, 4.5756 log P(atm) = 33.36 - 183500/T. The selected third law heat of sublimation, ΔHs° (298) is 185.9 kcal mol(-1). Our recommended equation for the vapor pressure is 4.5756 log P (atm) = 31.86 - 180200/T based on our mean third law heat and tabulated values for the entropies and enthalpies.