Vapor pressure and thermodynamics of Bk249 metal
Abstract
The vapor pressure of ^{249}Bk metal has been measured over the range 11001500 K, using combined target and mass spectrometric Knudsen effusion techniques. Vapor pressure data are combined with an appropriate estimate for the solid heat capacity and the estimated crystal entropy S°_{298}, to produce enthalpy, entropy, and free energy functions from 298 to 2000 K. The vapor pressures are described by the equations: Log_{10} P(atm) = (15 718 ±253)/T+578±0.21 [solid, 11071319 K], Log_{10} P(atm) = (14 902 ±244)/T+5.14±0.17 [liquid, 13451528 K] from which we calculate ∆ H°_{298} (2nd law) = 73 960±1150 cal/mol [solid], ∆ H°_{298} (2nd law) = 73 980±1120 cal/mol [liquid], and ∆ H°_{298} (3rd law) = 74 220±180 cal/mol [solid and liquid].
 Publication:

Journal of Chemical Physics
 Pub Date:
 August 1982
 DOI:
 10.1063/1.443975
 Bibcode:
 1982JChPh..77.1464W