Ytterbium selenites

Smolyakova and Serebrennikov [78SMO/SER] measured the enthalpy change of the reaction between an aqueous solution of ytterbium chloride and Na2Se03(cr). The description of the experiments and calculations is somewhat meagre. Their data have been re-evaluated as described in Appendix A and yielded the result Af//° (Yb2(Se03)3-8H20, am, 298.15 K) = (5115 7) kJ-mol.  

As an amorphous phase is apparently formed when ytterbium selenite is precipitated from aqueous solution, the result of this investigation is included in the review but not selected. 

Oppermann et al. [20020PP/ZHA2] report the enthalpy of formation of Yb2(Se03)3(cr) at 298.15 K to be -(2779 42) kJ-mol from equilibrium measurements of decomposition reactions in the temperature range 825 to 1050 K, see also [20020PP/ZHA2] in Appendix A. This is the only result found and the review adopts the rounded value 

Since this quantity was evaluated using non-TDB auxiliary data it has been included in Table E-2 of Appendix E. 

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