Heat Capacity and Thermodynamic Properties of Bismuth in the Range 333 to 923 K

Abstract

Calorimetric studies on the behavior of the heat capacity of bismuth have been carried out in the range 333 to 923 K. Values of the enthalpy and entropy have been determined for selected temperatures. The enthalpy and entropy of fusion at 544.54 K are 11.360±0.014 kJ mol−1 and 20.86±0.03 JK−1 mol−1, respectively. Appropriate polynomial temperature functions of the Cp for solid and liquid bismuth are given. Earlier reported increasing Cp at temperatures above 800 K proved not to be reliable. The heat capacity at constant volume decreased from 25.80 to 21.14 JK−1 mol−1 over the region 544.54 to 873 K. Due to beginning of higher-order transformation, the Cv of solid bismuth showed an excess over the harmonic value (3R).