Iron exhibits +2 (ferrous) and +3 (ferric) oxidation states. The key concept is that a higher positive charge on a cation leads to a smaller ionic radius and higher charge density. This makes Fe³⁺ a smaller, more polarizing ion than Fe²⁺. Therefore, ferric (Fe³⁺) compounds are generally more covalent, more easily hydrolyzed, and less volatile and ionic than their ferrous (Fe²⁺) counterparts. Ferric oxide (${\mathrm{Fe}}_2{O}_3$) is also less basic than ferrous oxide ($\mathrm{FeO}$).

Final Answer: The incorrect statement is "Ferrous compounds are more easily hydrolysed than the corresponding ferric compounds."