Ferric chloride forms both positively and negatively charged sols. Explain.

Explanation

When `FeCl_3` is added to excess of hat water, a positively charged sol of hydrated ferric oxide is formed due to adsorption of ferric ions. `Fe_(2)O_(3).xH_2O //Fe^(3+)` is a positively charged sol.
When `FeCl_3` is added to alkali solution, a negatively charged sol of ferric oxide is formed due to adsorption of hydroxyl ions . `Fe_(2)O_(3).xH_2O //OH^(-)` is a negatively charged sol.