The hydrolysis reaction for a hydrated metal ion in aqueous solution can be written as:
:p M + q HO ⇌ M(OH) + q H
and the corresponding formation constant as:
and associated equilibria can be written as:
:MO(OH)(s) + z H ⇌ M + (z–x) HO
:MO(OH)(s) + x HO ⇌ M + z OH
:p MO(OH)(s) + (pz–q) H ⇌ M(OH) + (pz–px–q) HO