Forms of Ions in Aqueous Solution Hydrolysis

The molecular form of any ion in aqueous solution depends largely upon the size and charge (oxidation state) of the central atom. These two properties influence the extent of any interaction with the solvent water molecules. A large singly charged ion is likely to be simply hydrated. In the case of a transition metal ion, there are commonly six water 

Forms of ions other than the simply hydrated ones may be understood in terms of the increasing interaction between the central ion and its hydration sphere as its oxidation state increases and its size decreases. This interaction is a chemical change known asliydroly.si.s. The first stage of hydrolysis may be written as  

There is then the possibility that water could be eliminated from the two OH groups  

Further hydrolyses involving more pairs of water molecules would yield the 0X0 ions +, and +.  

Another possibility is that a water molecule could be eliminated between two hydrolysed ions to give a dimeric product  

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