When freshly precipitated `Fe(OH)_(3)` is shaken with aqueous solution of `FeCl_(3)`, a colloidal solution is formed. The process is known as :

Explanation

`Fe^(3+)` ions present in the solution are adsorbed on `Fe(OH)_(3^.)` The positively charged particales formed mutually repel and get disintegrated resulting in a reddish brown colloidal sol.
`" "Feunderser(ppt.)(OH)_(3)+underset(("electrolyte"))Fe_^(3+)to[Feunderset("Colloidal sol.")(OH)_(3)]Fe^(3+)`
This process of converting a freshly precipitated substance into colloidal solution is called peptisation.