Measurement of Enthalpies of Evaporation of Bi and Bi2by an Optical Absorption Technique
- 1 December 1966
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 45 (11) , 4141-4145
- https://doi.org/10.1063/1.1727468
Abstract
The enthalpies of evaporation of Bi and Bi2 were determined by the second‐law method using an optical absorption technique to measure the change of vapor density with temperature for each species. The 3067‐Å line was used for Bi and the band head at 2731 Å was used for Bi2. The enthalpy of dissociation of Bi2 is the difference between the two enthalpies of evaporation. The evaporation values obtained wereBi(l)=Bi(g)ΔH∘298=49600±1100cal,Bi(l)=12Bi2(g)ΔH∘298=24700±1000cal,12Bi2(g)=Bi(g)ΔH∘298=24900±2100cal.The optical absorption technique was checked on lead, using the 2833‐Å line. For lead, the ΔH°v,298 measured was 47 240±850 cal, as compared with an accepted value of 46 600±300 calKeywords
This publication has 4 references indexed in Scilit:
- Simultaneous Determination of f Values and Vapor Pressures from Optical Absorption MeasurementsThe Journal of Chemical Physics, 1965
- Vapor Pressure of Liquid BismuthThe Journal of Chemical Physics, 1963
- IntroductionPublished by American Chemical Society (ACS) ,1956
- The heat of dissociation of Bi2 determined by the method of molecular beamsJournal of the Franklin Institute, 1934