Vapour pressure and standard enthalpy of sublimation of H3BO3

作者： R. Pankajavalli , S. Anthonysamy , K. Ananthasivan , P.R. Vasudeva Rao

DOI: 10.1016/J.JNUCMAT.2006.12.025

关键词: Isothermal process 、 Vapor pressure 、 Thermodynamics 、 Atmospheric temperature range 、 Thermal analysis 、 Transpiration 、 Sublimation (phase transition) 、 Chemistry 、 Standard enthalpy of formation 、 Enthalpy of sublimation

摘要: Abstract A horizontal thermal analysis instrument was adapted as a transpiration apparatus for the measurement of vapour pressure solid boric acid, H3BO3. The experimental parameters necessary establishing dynamic isothermal congruent vapourisation equilibrium H3BO3 were identified. Using these optimized experiments, pressures measured in temperature range 326–363 K. dependence values could be expressed using expression, log(p/Pa) = 26.83(±0.09) − 9094(±246)/T (K). standard enthalpy sublimation, Δ H sub 0 , estimated to 174.1 ± 4.7 kJ mol−1 at mean present measurements, viz., 345 K.