Sublimation Pressure and Standard Enthalpy of Bismuth Triiodide by Torsion-Effusion Method

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J. Korean Ceram. Soc. > Volume 28(2); 1991 > Article

Journal of the Korean Ceramic Society 1991;28(2): 109.

Torsion-Effusion 법에 의한 Bismuth Triiodide의 승화압과 표준 엔탈피

김준학

호주 NSW 대학교 재료과학공학과

Sublimation Pressure and Standard Enthalpy of Bismuth Triiodide by Torsion-Effusion Method

ABSTRACT

Steady-state sublimation vapour pressures of anhydrous bismuth triiodide have been measured by the torsion-effusion method from 488.8 to 570.5 K and equilibrium sublimation pressures were obtained from the steady-state data. The standard sublimation enthalpy changes derived by both second(modified sigma function) and third(average enthalpy method) law methods were 159.316${pm}$0.055, 137.67${pm}$1.43 kJ$.$mol-1 respectively. The standard sublmation entropy change derived by modified sigma function was 232.88${pm}$0.10 J$.$K-1$.$mol-1. The reliable standard sublimation enthalpy change based on a correlation of {{{{ { TRIANGLE }`_{cr } ^{g } }} H{{{{ { 0} atop {m } }}(298.15K) and {{{{ { TRIANGLE }`_{cr } ^{g } }} S{{{{ { 0} atop {m } }}(298.15K), a recommended p(T) equation has been obtained for BiI3(cr) ; lg(p/Pa)=-(C$.$K/T)+5.071lg(T/K)-2.838${times}$10-3(T/K)-7.758${times}$103(K/T)2+1.4519 where C={{{{{ { TRIANGLE }`_{cr } ^{g } }} H{{{{ { 0} atop {m } }}(298.15K)/0.019146 kJ$.$mol-1}-456.27.