Redox Electrons in Aqueous Solution

The value of xh o is important for estimating theoretically the energy levels of hydrated ions and redox electrons in aqueous solutions. 

In the case of aqueous solutions containing dissolved particles (solutes), a number of localized electron levels associated with solute particles Eirise in the mobility gap of aqueous solutions as shown in Fig. 2-34. These localized electron levels of solutes may be compared with the localized impiuity levels in semiconductors. In electrochemistry, the electron levels of the solutes of general interest are those located within the energy range from - 4 eV to - 6 eV (around the electron levels of the hydrogen and oxygen electrode reactions) in the mobility gap. 

---