Sulfur trioxide, thermodynamic properties

A study on the thermodynamic properties of the three SO phases is given in Reference 30. Table 1 presents a summary of the thermodynamic properties of pure sulfur trioxide. A signiftcandy lower value has been reported for the heat of fusion of y-SO, 24.05 kj /kg (5.75 kcal/kg) (41) than that in Table 1, as have slightly different critical temperature, pressure, and density values (32). 

The thermodynamic properties of sulfur trioxide, and of the oxidation reaction of sulfur dioxide are summarized in Tables 3 and 4, respectively. Thermodynamic data from Reference 49 are beheved to be more accurate than those of Reference 48 at temperatures below about 435°C. 

Both a- and 7-alumina can react with sulfur trioxide to form aluminum sulfate. The conditions for the formation and thermal decomposition of aluminum sulfate are given in Fig. 8. The thermodynamic properties of... 

Figure 16.17b), as does 0t-SO3 in which the chains are arranged into layers in the solid state. Differences in the thermodynamic properties of the different polymorphs are very small, although they do react with water at different rates. Sulfur trioxide is very reactive and representative reactions are given in scheme 16.95. 

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