Bismuth, thermodynamic data

The physical properties of bismuth, summarized ia Table 1, are characterized by a low melting poiat, a high density, and expansion on solidification. Thermochemical and thermodynamic data are summarized ia Table 2. The soHd metal floats on the Hquid metal as ice floating on water. GaUium and antimony are the only other metals that expand on solidification. Bismuth is the most diamagnetic of the metals, and it is a poor electrical conductor. The thermal conductivity of bismuth is lower than that of any other metal except mercury. 

No thermodynamic data have been found for bismuth selenates. 

Stability constants for the bismuth(m) iodide species Bil , n = 1—6, have been calculated from solubility data, and thermodynamic data for BiClg" can be obtained from heats of mixing of bismuth perchlorate and hydrochloric acid. ... 

The high-temperature thermodynamic data obtained in the present study and in [5] were reduced to T — 298 K using the temperature dependence of the specific heat of bismuth telluride in the 550-28 C range [12], the thermodynamic properties of the elements [il], and the temperature dependences of the specific heat of Bi2Se3, Sb2Se3, and Sb2Te3 deduced in the —25°C... 

O.J. Kleppa, Approximate Thermodynamic Data from the Systems Copper-bismuth, Copper-lead and Copper-thallium , J.Am.Chem.Soc.. Vol. 74,1952,6047-6051. 

Table 15.1 Thermodynamic data for bismuth(lll) phases and hydrolysis species at 25 °C and comparison with data available in the literature.

From the accepted data for bismuth(lll) phases and species, thermodynamic data can be derived. These data are listed in Table 15.1 and are compared with data available in the literature for some of the species. In general, there is good agreement between the literature data and those values derived in the present review. The Gibbs energy found for BiOH and Big(OH)j 2 in this review is slightly more positive than those selected by Bard, Parsons and Jordan (1985) most likely because in this latter review stability constants were used to derive the data that were from measurements at fixed rather than zero ionic strength. 

Table 15.5 lists the thermodynamic data reported for bismuth metal and the bismuth(III) ion. These data have been used to derive the data reported in Table 15.1. 

Sb4. Information on the composition of the bismuth vapor is less definite [5] but it is known that the principal component, under the conditions used in our study, is the monatomic bismuth. This is why the equilibrium in the dissociation of gaseous MeX is shifted in the direction of the formation of binary bismuth selenide and telluride, whereas the equilibrium in the case of SbTog is shifted in the direction of dissociation. Thermodynamic calculations confirming this assumption are presented in Table 4. These calculations are based on the data given in [1, 10, 12, 15]. The values of are calculated for the total pressures which correspond approximately to the values of the pressures obtained in our experiments at 800 C. 

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