K for three total concentrations

Thermal thermodynamic quantities of Sep2(g) were calculated by the review based on spectroscopic data by Willner [81W1L]. In the temperature range 298.15 to 2000 K, the heat capacity expression  

This equation yields the boiling point 377.9 K of Sep4 at 1.0 bar, in good agreement with the observed value 379 K [53PEA]. 

From this equation the enthalpy and entropy of reaction at the mean temperature, 320 K, are calculated to be (45.0 1.5) kJ-mol and (119 6) J-K -moP, respectively. These results are accepted to be valid at standard conditions, i.e. (V.37) = 

The entropy value 296.1 J-K. -moP for Sep4(g) was calculated by O Hare [680HA] from molecular constants. By use of spectroscopic data by Bowater et al. [68BOW/BRO] and by Adams and Downs [72ADA/DOW], the review obtained the following selected standard entropy value  

The review also calculated the heat capacity expression in the temperature range 298.15 to 2000 K  

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Figure V-IO Predominance areas in the pH-pe-diagram for selenium at standard conditions and 298.15 K for three total concentrations.

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