Main-group elements monoatomic ions

Estimation of the entropy of solvation requires calculation of the entropy of the ion in the gas phase. For a monoatomic ion, the main contribution to the entropy comes from its translational energy. Simple ions formed from the main group elements have the electronic structure of an inert gas and therefore do not have an electronic contribution to the entropy. On the other hand, ions formed from transition metals may have an electronic contribution to the gas phase entropy, which depends on the electronic configuration of the ion s ground state and of any other electronic states which are close in energy to the ground state. The translational entropy is given by the Sackur-Tetrode equation, which is obtained from the solution of the SWE for a particle in a box (see section 2.2)... 

Table 3.5 MSA Parameters Relating to the Solvation of Monoatomic Ions of the Main Group Elements in Water on the Basis of Equation (3.5.14)...

In summary, the empirical approach to ionic solvation based on the MSA is quite successful for monoatomic ions of the main group elements. It helps one to understand the important differences between the way cations and anions are solvated in water. It can also be applied to other ions, including polyatomic ions, provided the solvation is essentially electrostatic in character. Thus, one may estimate effective radii for anions such as nitrate and perchlorate from the Gibbs solvation energy using the value of 8s calculated for the halide ions. Considering the simplicity of the model, it provides an useful means of understanding the thermodynamics of solvation. 

Predict the charges of the monoatomic ions formed by these main-group elements. 

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See also in sourсe #XX -- [ , ]

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